French President Nicolas Sarkozy denied allegations on Tuesday that his party received illegal campaign donations in cash from France's richest woman via Labour Minister Eric Woerth as part of a vast system of patronage.

The allegation was made by a former bookkeeper for Liliane Bettencourt, main shareholder in the cosmetics giant L'Oreal, and raised pressure on Sarkozy to bring forward a reshuffle of his government, battered by sleaze allegations.

The bookkeeper, identified by a prosecutor's spokesman as Claire Thibout, told the news website Mediapart she had been involved in withdrawing 150,000 euros ($200,000) in cash to be given to Woerth in unmarked envelopes as a donation to Sarkozy's 2007 election campaign.

Thibout's lawyer confirmed she had given a statement to police on Monday making the allegation. Bettencourt's lawyer could not immediately be reached for comment.

Sarkozy said Woerth was a victim of calumny "without the slightest reality" and he wished people would take more interest in big issues such as health care and pensions rather than in "those who create scandals".

In an emotional live television interview, Woerth denied the allegations, said he was victim of a "cabal" by the Socialist opposition and insisted he would not resign because he was innocent and the real target was Sarkozy.

"I never, never received a single illegal euro," the centre-right minister and treasurer of the ruling UMP party said, his voice quivering with anger. "Everything is false. It's defamation.

"I am the minister who fought hardest against tax evasion. The Swiss resent me to death," he said, referring to his stint in the budget ministry.

French law limits donations to parties to 7,500 euros per person per year. Only 150 euros may be given in cash.

Earlier, Socialist and Communist members walked out of parliament after a centre-right minister accused the opposition of "playing the game of the extreme right" by asking repeatedly about the allegations during a question-and-answer session.

"These accusations are completely unacceptable," Socialist floor leader Jean-Marc Ayrault told reporters. "When we ask for explanations, for clarification from the government, we are accused of playing the game of the extreme right."

Woerth is leading a major pensions reform and is a key ally of the president, whose approval rating hit an all-time low of 26 percent last week amid sleaze allegations involving several ministers.