The 74 year-old leader is to reveal in an address to the nation on radio and television whether he will stand in the presidential election to be held in six weeks.

The content of his declaration has been kept secret by the Elysee palace, but the near universal consensus was that he will explain why he has decided not to seek an unprecedented third mandate.

With official nominations for the race due by next Friday, Chirac has kept open till the last moment the option of running again -- despite polls that show he would have no chance of winning again.

But in recent weeks he has given several hints that he intends to step down, telling a television interviewer last month that "there is life after politics" and that he hopes to serve France "in another capacity".

The president has also hosted three international meetings on issues known to be close to his heart -- Lebanon, the environment and French-African relations -- and this week he attended what was widely seen as his farewell EU summit.

If there was little suspense about Chirac's decision, speculation centred on whether he will use the broadcast to endorse the right-wing candidate for the presidency Interior Minister Nicolas Sarkozy, a former protege who heads the ruling Union for a Popular Movement (UMP).

Sarkozy, 52, has a narrow lead in the polls over the socialist Segolene Royal but now faces a new challenge from the centrist candidate Francois Bayrou, head of the Union for French Democracy (UDF), whose ratings have surged in the last month.

Chirac and Sarkozy -- whose relations have long been tense -- had talks last week, and Sarkozy said he was informed what the president plans to say in his broadcast.

Speaking on France 2 television, the UMP leader said Chirac's public backing "would have a certain weight among some French people who are still uncertain (how to vote)". However party insiders said they do not expect the president to make an explicit statement of support.

Chirac's announcement was expected to unleash a flood of tributes from politicians and the public. While misgivings remain about his legacy after 12 years as president, he commands widespread affection and even political opponents praise his defence of French interests in the world.

Chirac also led international opposition to the US spearheaded invasion of Iraq in 2003.

Jean-Pierre Raffarin, who was Chirac's prime minister from 2002 to 2005, said Sunday's broadcast would be a "a very important moment of political history".

According to Overseas Minister Francois Baroin, "the French feel tenderly towards him. Even if they want to turn the page, they still like him."

Bayrou, who served as education minister under Chirac from 1995 to 1997, said that "on foreign policy he was an honorable voice, and a great voice at the moments when France needed one" -- a clear reference to Chirac's defiance of the United States over Iraq.

On domestic affairs, Bayrou said Chirac "was constantly concerned by the need not to tear the French people apart" -- an intentional jibe at Sarkozy, who is accused of abandoning Chirac's consensual political approach.

Chirac began his political career in 1962 as an advisor to prime minister Georges Pompidou, and had his first cabinet post in 1967. He served twice as prime minister, 18 years as mayor of Paris and two consecutive mandates as president.