Paris: French President Emmanuel Macron's party is on course for an overwhelming parliamentary majority after Monday's first round of voting for the National Assembly that left traditional parties in disarray.
Forecasts based on partial results showed Macron continuing his centrist revolution, with his Republique en Marche party (Republic on the Move, REM) and its ally MoDem tipped to win between 390 and 445 seats in the 577-member National Assembly in next Sunday's second round.
"France is back," Prime Minister Edouard Philippe declared triumphantly.
"For the past month, the president has shown confidence, willingness and daring in France and on the international stage," Philippe said, calling the result a vindication of Macron's "winning strategy".
The vote was marked by record low turnout of 49 percent, reflecting the fatalism among Macron's opponents in the face of his seemingly unstoppable advance, experts said.
The right-wing Republicans -- who had hoped to rebound from their defeat in the presidential vote -- were shown trailing in second with a predicted 80-132 seats while Marine Le Pen's far-right National Front (FN) was forecast to garner between one and 10 seats.
The FN's result showed the party struggling to rebound from Le Pen's bruising defeat by Macron in the presidential run-off.
FN vice-president Florian Philippot admitted to "disappointment" and called on voters to "mobilise massively" for the June 18 second round.
The worst losses, however, were for the Socialists of Macron's predecessor Francois Hollande, who were shown dropping a staggering 200 seats.
Conceding the party was facing "unprecedented" losses, PS chief Jean-Christophe Cambadelis appealed to voters to rally behind Macron's rivals to avoid the president monopolising power.
Parliament risked having "no real oversight powers and no democratic debate worth speaking of," he warned.
Republicans leader Francois Baroin also cautioned against all the power being "concentrated in one party".
The estimates based on partial results showed Macron's year-old REM and MoDem winning 32.2-32.9 percent in the first round, ahead of the Republicans on 20.9-21.5 percent and the FN on 13.1-14 percent.
Few MPs are expected to be elected outright on Sunday.
If no candidate wins over 50 percent, the two top-placed contenders go into the second round -- along with any other candidate who garners at least 12.5 percent of registered voters.
France's youngest-ever president has been credited with restoring a lost sense of national pride since winning the top office last month at 39.
He has won praise for appointing a balanced cabinet that straddles France's long-entrenched left-right divide and taking a leading role in Europe's fight-back against US President Donald Trump on climate change.
If the seat projections are confirmed next week, he will have a strong mandate to push through the ambitious labour, economic and social reforms he promised on the campaign trail.
More than 50,000 police were on patrol during the vote, with France still jittery after a wave of jihadist attacks at home and across the Channel in Britain.
Macron, who had never held elected office before becoming president, fielded political novices in around 200 constituencies -- part of his bid to rejuvenate the assembly.
They include Marie Sara, a retired bullfighter, who is taking on FN stalwart Gilbert Collard in southern France and 33-year-old junior digital economy minister Mounir Mahjoubi who went up against PS boss Cambadelis in northeast Paris.
Macron is also trying to usher in an era of cleaner politics. His government's first bill proposes to ban lawmakers from employing family members or performing consultancy work while in office.
The measures follow the scandal that destroyed the presidential bid of Republicans candidate Francois Fillon, who has been charged over payments to his wife and two of his children for suspected fake jobs as parliamentary assistants. Fillon denies the charges.
Macron's party has largely avoided controversy but one of his ministers who is running for re-election in Brittany, Richard Ferrand, is being probed over a property deal involving his girlfriend.
Forecasts show Le Pen's party will struggle to win the 15 seats it would need to form a parliamentary group and help shape the assembly's agenda.
The radical-left France Insoumise (France Unbowed) party of Jean-Luc Melenchon who finished fourth in the presidential race also fell short of expectations.
His camp was tipped to only take 10-23 seats.
Macron has urged voters to back his reform proposals including an overhaul of the rigid rules governing the job market, blamed by many economists for holding back growth.
The president was economy minister in the Socialist government that began loosening the labour laws last year, sparking mass demonstrations that lasted for months.