Senior MP Christophe Castaner has accused Melenchon of wanting a "Soviet revolution", while Economy Minister Bruno Le Maire called him a "French (Hugo) Chavez" after the late Venezuelan autocrat. The contest between Together and NUPES has turned increasingly bitter over the last week, with Macron's allies seeking to paint their main opponents as dangerous far-leftists. Macron cast his ballot in northern seaside town Le Touquet alongside his wife Brigitte, while Melenchon voted in Mediterranean port city of Marseille. The election caps an intense two-month sequence to elect a new president and parliament, with voter fatigue seen as one of the reasons for what is expected to be record-low turnout Sunday. Far-right leader Marine Le Pen is also eyeing major gains for her National Rally party, which had just eight seats in the outgoing parliament. The first-round vote served to whittle down candidates in most of the country's 577 constituencies to two finalists who are going head-to-head Sunday. Political mudslinging - Macron was left disappointed last weekend after the first round placed Together and NUPES neck-and-neck at around 26 percent. "The vote is extremely open and it would be improper to say that things are settled one way or the other," Melenchon told reporters Friday during a final campaign stop in Paris. The nightmare scenario for the president - seen as unlikely although not theoretically impossible - would be the left winning a majority and Melenchon heading the government. Falling short of the majority would force Macron into tricky alliances with other parties on the right to force through legislation. New left-wing coalition NUPES is hoping to spring a surprise, with the red-green collective promising to block Macron's agenda after uniting behind 70-year-old figurehead Jean-Luc Melenchon. Projections from polling firms suggest his "Together" coalition is on course to be the biggest party in the next National Assembly, but possibly short of the 289 seats needed for a majority. The vote will be decisive for Macron's second-term agenda following his re-election in April, with the 44-year-old needing a majority to secure promised tax cuts and welfare reform and raise the retirement age. At almost 19 percent by midday according to interior ministry figures, turnout was slightly higher than in last week's first-round ballot, although forecasters suggest participation will remain below 50 percent by the time all polling stations close at 8:00 pm (1800 GMT). French voters were picking a new parliament Sunday in a run-off ballot, with centrist President Emmanuel Macron's coalition seeking to maintain its majority in the face of a challenge from a newly formed left-wing alliance.