Ulster Unionist and Conservative MPs were accused today of trying to maintain a "two tier" House of Commons after they demanded Sinn Fein must declare their members' interests.
With Sinn Fein's four MPs poised to take up their offices at Westminster next Monday, a letter to the standards and privileges committee, signed by Ulster Unionists and Conservative MPs including UUP leader Mr David Trimble, has insisted that republicans must be forced to sign the register of members' interests.
The letter, prompted by the vote last month to grant Sinn Fein offices in the House of Commons, highlighted a loophole which would mean Sinn F&aeacute;in MPs would not have to declare their members' interests when taking up their facilities at Westminster because they do not have to swear the oath to the Queen.
The MPs said Westminster was in danger of creating a new class of MP.
However Sinn F&aeacute;in's Ms Michelle Gildernew hit back today, accusing the UUP and Conservatives of trying to maintain a system which discriminated against their MPs.
Insisting her party had no difficulty with signing the register as members already do so at the Northern Ireland Assembly, the Fermanagh and South Tyrone MP declared: "For people to be jumping up and down about Sinn Féin signing a code of ethics within the House of Commons, I find it fairly ironic given all the sleaze, scandal and basically bad behaviour by MPs in recent years, particularly the Tories.
"The reality is that this is the Tories and the UUP getting together because they are furious that we are at last getting what we are entitled to. They are attempting to put a spoke in the wheel."
Ms Gildernew told BBC Radio Ulster that since 1997 Sinn F&aeacute;in MPs and their constituents had become a different class of MP after their right to take up House of Commons facilities was withdrawn.
Sinn F&aeacute;in earned access to facilities at Westminster in a House of Commons vote last month.
Ms Gildernew will join party president Mr Gerry Adams, Stormont Education Minister Mr Martin McGuinness and vice president Mr Pat Doherty in Westminster on Monday to claim their facilities.
Mr Adams claimed last month in Cuba that the offices would enable republicans to establish a "beachhead" to convince opinion makers in Britain of the need for a united Ireland.
PA