Nothing succeeds like success, and the boom in China's economy seems to have spelt doom for the leftists and Maoists in the Beijing leadership who have been engaged in a bitter struggle to decide how China should be run until well into the 21st century. In a turning point in Chinese politics in recent weeks, reformers at the top, including editors, academics and advisers to President Jiang Ze min, have seized the initiative and are not just attacking the dwindling old guard in coded speeches but tolerating new talk of political reform.

These developments, momentous in Chinese terms, come on the eve of the first Communist Party congress in 20 years which will not have the guiding presence of the "great re former", Deng Xiaoping.

A surge of articles in the officially controlled media has confirmed that since Deng's death in February, a faction of the left within the leadership has been struggling hard, mainly through the internal circulation of conservative speeches, to reverse the reforms which the paramount leader began in 1978.

"Since last year we have seen that leftists have clashed with the theories of Comrade Deng Xiaoping," said Xing Bensi, editor of the party magazine Seeking Truth and a close adviser to Mr Jiang, in the first open acknowledgement a few days ago of the ideological feuding.

The victory of the reformers has been trumpeted in typical communist fashion. For three consecutive days last week, the party organ, the People's Daily, hailed the reform accomplishments of Deng Xiaoping and warned there could be no turning back. In case the message was not getting across, one editorial attacking Stalinist-style central planning was splashed across the front page.

"We ran a planned economy for more than 20 years and created the foundations of industrialisation," it said, "but it was still an economy of scarcity and an economy of poverty." Now the words "market economy" had been "writ large on the flag of socialism for the first time".

Analysts say the new winds of reform began blowing when President Jiang tackled ideoogical objections to privatisation in a secret speech at the central party school on May 29th. Some extracts have been published since then and Communist Party cadres have been ordered to study it in preparation for the 15th party congress at the end of September.

In his address, Mr Jiang used a loaded phrase, saying that China was still in the "primary stage of socialism". This echoed the pro-reform arguments heard in the 1980s from his predecessor as party secretary, Zhao Ziyang, who was ousted from political life after sympathising with the pro-democracy students.

With many state industries facing bankruptcy and rising unemployment, he confirmed that public ownership remained a sacred tenet of Chinese communism; but he argued that non-public, i.e. private, ownership had to be an important component of the socialist market economy.

A three-day party propaganda conference has since endorsed the reform line, with a rallying call to party cadres to "unify your thoughts to the May 29th speech by President Jiang Zemin".

Keeping up the drumbeat yesterday, the People's Daily published remarks by a leading party official, Zhao Keming, who said Jiang's speech was a "profound political declaration of the third generation of Communist Party leadership" which "would create a beneficial international environment for China's modernisation drive". It should set at rest the minds of foreign leaders concerned about the cause of reform and opening up.

In this climate a professor at Beijing University, where the pro-democracy protests flourished a decade ago, has emerged as the first senior academic on the campus since 1989 to call for political change.

Prof Shang Dewen (65) made public a plan he has long nourished for a staged transition to democracy. "If there is no change to the political system, I fear the attempt at the 15th party congress will be doomed," he told the South China Morning Post in an interview last week which was picked up from the Hong Kong newspaper by the BBC and broadcast back to China.

Prof Shang proposed a new constitution drawn up by a body summoned by the party but containing representatives of all sections of society, and free elections for the head of state and a parliament with a four-year term. His plan, yet to be published in any Chinese organ, also advocated an independent judiciary and a free press.

The greatest problem facing China was the contradiction between the market economic system and the political system, he believed. "All the malpractices, corruption and illegal behaviour are generated by the fact that the two cannot operate together without malfunctioning."

In attempting to root out corruption, Mr Jiang had "squashed a few flies" but "look at the case of Chen Xitong", the economics professor said, referring to the former Beijing party chief who lost his job in a $2 billion corruption scandal two years ago. "Nothing has happened because no one in the politburo agrees on what to do."

Such outspokenness required courage. Some of his four children wanted him to stay quiet, mindful of the fate of dissidents such as Wei Jingsheng, who has been in prison, apart from a short break, since he put up a poster calling for democracy in 1978. Other critics of the system are serving long prison sentences.

The professor's 45-year record as a party veteran, and the changing climate, may protect him from punishment, but for mainstream dissidents nothing has yet changed. Only on Monday, Jin Cheng was arrested for the second time for calling for a corruption trial for the disgraced Beijing party boss, whom he also blames for the 1989 crackdown in Tiananmen Square.

Another dissident, Ren Wanding, who served seven years for his role in Tiananmen Square, was warned not to leave his Beijing home this week during the visit of the US President's national security adviser, Mr Sandy Berger.

"The police have told me this was an order from above," he said. "I can't stand it any more."

With its incremental tradition, the intrigue at the top will take time to work through the Chinese political cosmos. Many issues still have to be resolved as the leadership takes its annual busman's holiday at the beach resort of Beidaihe, east of Beijing. Intense jockeying over personalities is taking place there in anticipation of the congress which will produce the 200 men and women who will guide China for the next five years.

One of the unresolved questions is what role Li Peng will be given when his term as Prime Minister ends next year, and if he will be replaced by Zhu Rongji, one of the prime architects of reform. Leaders are putting pressure on Qiao Shi (73), the moderate chairman of the National People's Congress and Mr Jiang's main rival for supremacy, to yield his position to Mr Li.

Though he was close to the leftists a few years ago, Jiang Zemin is now pushing to enshrine Deng's theories in party ideology, and thus strengthen his own position against the opponents of Deng's reforms. He has tightened his grip on the People's Liberation Army, with his proteges installed in top positions.

The implications of this power struggle for the west are profound. With the leftists seemingly rendered impotent, China seems set on more opening up and further economic reforms, and just possibly the long overdue renewal of a debate on political reform, crudely interrupted in Tiananmen Square in 1989.