In the summer of 1947 Sean MacBride seemed poised to make a breakthrough in Irish politics. Fianna Fail had been in power since 1932 and by then many of its followers were disillusioned that all of de Valera's promises had not come to fruition. Fine Gael was in serious decline and Labour had split into two parties.

Sean MacBride's new party, Clann na Poblachta, was especially threatening to Fianna Fail: it belittled de Valera for any hints of heresy or pragmatism on the national question; it banged the anti-Partition drum louder than all comers; it was recruiting activists and voters from Fianna Fail; and in MacBride it reckoned it had the only leader with the charisma, intellect and national record to take on de Valera.

Having prospered at the local elections in 1947, Clann na Poblachta won two spectacular victories in by-elections at the end of October. Among those elected was Sean MacBride.

On the very day of his election to Dail Eireann on a new republican platform to unite the country and transform politics, MacBride wrote to McQuaid that having become "a public representative for a portion of Your Grace's Archdiocese, I hasten, as my first act, to pay my humble respects to Your Grace and to place myself at Your Grace's disposal".

He added that both as a Catholic and as a public representative he would "always welcome any advice which Your Grace may be good enough to give me and shall be at Your Grace's disposal should there be any matters upon which Your Grace feels that I could be of any assistance". Furthermore, it was his "sincere hope that Your Grace will not hesitate to avail of any services should the occasion arise".

McQuaid quickly acknowledged this "gracious letter", thanking MacBride for "the courtesy which you have so promptly shown to the See of Dublin". Moreover, he would not "fail to take advantage of your generous suggestion that you are at my disposal for any matters in which you could assist; I should not, however, wish to worry you, unless the good of the Faith were in question. When that occasion arises, I will not hesitate to avail of your services, now so frankly offered."

NOT content with this exchange, MacBride replied immediately, noting that he did not "deserve the thanks which Your Grace so graciously gives me, for in writing to Your Grace I was but doing what I considered to be my very first duty". It was "with no sense of false humility that I say that I shall stand in need of help and guidance in the discharge of my new duties. Accordingly, I trust that Your Grace will not hesitate to call upon me at any time to impart such advice, formally or informally, as may from time to time occur to Your Grace. I know how burthened [sic] with work Your Grace is and accordingly I should deem it a favour if Your Grace did not trouble to acknowledge this note of thanks."

Any supporters of MacBride who might wish to excuse this rush to ingratiate himself with McQuaid on the grounds that he was a political neophyte fresh from the triumph of a famous by-election victory will find no solace in MacBride's repeat performance after the general election of some months later.

After the February 1948 election results MacBride wrote again: as his "first official act" he felt he should "place myself entirely at Your Grace's disposal". And he would always as "a Catholic, a public representative and the leader of a party" welcome "any advice or views" which McQuaid might impart "officially or informally".

For a party leader who had excoriated Fianna Fail for its failure to undo Partition, this was an astonishing letter. MacBride added that should McQuaid wish to discuss any matters, he trusted the archbishop would "not hesitate to summon me". He would always "deem it a favour to be given the opportunity to place myself at Your Grace's disposal". MacBride concluded this letter by asking for prayers so "that my colleagues and I may be given the wisdom and light to discharge our duties faithfully as Catholics and public representatives".

It would be important to note this letter was written in the immediate aftermath of the election and MacBride's reference to his colleagues would be a reference to his parliamentary party that numbered 10 after that election.

McQuaid's instruction to his secretary for the reply to MacBride reads: "Thank you for courtesy. If there be any matters on which I think you can help, I will gladly ask you to discuss them." McQuaid would have appreciated that the value of these blank cheques which he had received from MacBride - three such letters within less than four months - was considerably enhanced the following week when it emerged that Clann na Poblachta was to help form a government with MacBride as minister for external affairs and his party colleague, Dr Noel Browne, as minister for health.

And in the third year of that government's life, as McQuaid came to challenge Browne over the Mother and Child Scheme, his confidence can only have been strengthened by having such letters from Browne's party leader in his back pocket.

It is worth emphasising that all of MacBride's letters to McQuaid are handwritten. Since their tone and content are wholly inappropriate for a leader with Clann na Poblachta's roots, policies and membership - or for any party leader, other than one leading an avowedly Catholic party - MacBride may have been taking the precaution that he alone in Clann na Poblachta would see the letters. No secretaries would type them and presumably no copies would be filed in the party's records.

This file in McQuaid's papers does not include any letter from MacBride following the 1951 election - perhaps the trauma of the then very recent Mother and Child controversy prompted caution on his part. It is always possible, of course, that he wrote the customary letter and that it was not filed or was misfiled.

However, it would not seem to be the case that the absence of a letter in 1951 can be construed as evidence that MacBride had learned any lessons from the Mother and Child debacle which had split - and effectively destroyed - his own party following Browne's resignation as minister.

After the 1954 election - by now leading a party reduced to three seats - he returned to his old form:

"My Dear Lord Archbishop,

On the occasion of my re-election to Dail Eireann it is again my pleasant duty to place my services at the disposal of Your Grace. It is my aim to serve Catholicism and Ireland to the best of my ability and I shall deem it a favour to receive any guidance and advice which Your Grace may, at any time, think fit to give me."

The words "serve Catholicism and Ireland" were heavily underlined by McQuaid - or his secretary - and the letter is marked "File for reference".

On the same day, MacBride wrote to McQuaid's secretary, attempting to interest him in one of Noel Browne's election leaflets. It was entitled Work To Be Done and MacBride in his letter outlined his reason for forwarding it to archbishop's residence.

It was "to draw your attention to the inside pictorial map in which it is apparently inferentially claimed that the new Children's Hospital in Crumlin was initiated and built by Dr Browne". MacBride added that the hospital was in his Dublin South West constituency and he complained that "many attempts" had been made to claim it as Browne's achievement.

He concluded: "My recollection is that the project for this hospital was initiated by His Grace long before Dr Browne was ever heard of. Can you confirm my recollection on this point? If my recollection is correct in this respect should something not be done to let it be known that it was not Browne who was responsible for the erection of this hospital but that it was His Grace?"

This was clearly intended for McQuaid's attention. MacBride would have liked nothing better than an episcopal denunciation of Browne, for whom he now reserved a special loathing - which, it must be said, was reciprocated. But McQuaid had no intention of wandering into this minefield, and especially not at MacBride's prompting.

THE leaflet was drawn to his attention. His instruction for his secretary is masterly. "I have not read enclosed. Better reply that you think it would be more advisable not to worry the AB with the enclosed. At the time of opening [of Crumlin Hospital], it will be possible to make the position clear."

In his retirement Sean MacBride proved very touchy on the subject of church-State relations. Critics of how his party had handled the issue were accused of giving succour to Ulster unionism. This emerged in a public disagreement between himself and the present writer during the course of a lengthy, live radio interview in 1980.

I had first reminded him that Clann na Poblachta had joined with its colleagues at the first cabinet meeting of that inter-party government in sending a telegram to the Pope expressing their - presumably collective - desire "to repose at the feet of Your Holiness the assurance of our filial loyalty and of our devotion to your August Person". Was this not - for a party founded to hasten the end of Partition - an unpromising beginning? MacBride took umbrage. In fact, he had defended the sending of this telegram when the government secretary, Maurice Moynihan, advised against it.

Later I asked him whether the government's handling of the Mother and Child controversy had not damaged its anti-Partition strategy. He insisted that he was treating the Catholic bishops merely as another interest group. The argument turned on whether he had promised to obey or to consult the bishops in 1951. I think he thought it unsporting when I quoted his words in the 1951 Dail debate in which he had insisted that as a Catholic he was "bound to give obedience to the rulings of our church and of our hierarchy".

Old politicians' memories are important, but they have their limitations. The contemporary record - or the private hand-written letters in a bishop's archive - invariably speak louder.

In this case McQuaid's archive exposes MacBride's reputation. Are his credentials as a republican a sham? Or is it yet another example of the chameleon in MacBride? F.H. Boland was unimpressed on one occasion when MacBride, having been deferential in a phone conversation with McQuaid, had then spoken contemptuously of him once he had put the receiver down.

Or is it that he was just tops in hypocrisy?

Dr John Bowman is a historian and broad- caster and writer-presenter of the television documentary, John Charles McQuaid: What The Papers Say. This article is based on a paper to be delivered on Friday at the Royal Irish Academy in Dublin