His Union for a Popular Movement (UMP) and its centrist allies took between 45.6 and 46.4 per cent of Sunday's vote, according to estimates at the close of polls for the 577 seat lower house National Assembly.
The UMP, which holds 359 seats in the outgoing assembly, and its allies were predicted to secure between 383 and 501 seats in the run-off next Sunday, according to the polling firms CSA, Ipsos and Sofres.
The main opposition Socialist Party (PS), in disarray following Royal's defeat, faced the prospect of another humiliating electoral blow as pollsters predicted it could lose up to half of its current 149 seats.
With around 39 per cent of the national vote, polls suggested the Socialists would return between 60 and 170 deputies to the new assembly.
Confident of another electoral triumph following the second round of voting on June 17, Sarkozy has promised a special parliamentary session in July to push through reforms including tougher sentencing rules, restrictions on immigration and more autonomy for universities.
The cabinet of Francois Fillon, the prime minister, unveiled on Thursday details of a $15bn master plan to "shock" the economy back to life, the first part of the president's reform drive.
|Sarkozy, with wife Cecilia, right, and Judith, his|
stepdaughter, at a Paris polling booth [AFP]
Suffering from voter fatigue and possibly distracted by fine weather and the French Open tennis final at Roland Garros, many people did not bother to cast their ballots in an election widely seen as a postcript to the presidential vote.
Turnout appeared headed for a record low of around 63 per cent - down from 84 per cent in the presidential vote last month.
Prospects were also bleak for the Communist party, which was predicted to lose many of its 21 seats.
The new centrist MoDem party founded by Francois Bayrou, the third-placed presidential candidate, was credited with seven per cent of the vote and was expected to win four seats at most.