MARK Cavendish's frustrating start to the Tour de France continued on Tuesday as he found himself squeezed out on stage four in Sarzeau.

Not for the first time on this Tour, Cavendish came uncoupled from his Dimension Data lead-out train and found himself boxed in, unable to join a fight in which the impressive 23-year-old Fernando Gaviria held off world champion Peter Sagan for his second stage win of his debut Tour.

Things had looked good for Cavendish with his team lined up on the left after the peloton finally chased down the day's breakaway - fittingly made up of two Frenchmen and two Belgians on World Cup semi-final day - two kilometres from the finish.

But as the fight for space heated up, Cavendish was knocked out of position by Kragh Andersen. He was able to get back on the wheel of team-mate Mark Renshaw but just as quickly found his path blocked by Gaviria's Quick-Step train.

"I was blocked by my own lead-out man effectively, but it was my own fault - I shouldn't have been there," said Cavendish as he held six-week-old son Casper outside the team bus.

"Quick-Step are hard to beat anyway - it's another stage win for them and I'm left holding the baby."

Before the start of the Tour, Cavendish said catching Eddy Merckx's all-time Tour record of 34 was "the only target left" in his career. But his wait to add to his tally of 30 is now less than a week shy of two years, and Gaviria's emergence means there is yet another generation ready to challenge him.

"I never said it would be this Tour!" Cavendish said in the morning when reminded of Merckx's record.

The 33-year-old's form remains uncertain after a season disrupted by crashes but the problems run deeper in the team.

Technical finishes might have had something to do with Dimension Data's lead-out woes on stages one and two, but the bigger issue has been the rash of injuries in the team this year which means Cavendish and his key men Renshaw, Edvald Boasson Hagen and Reinardt Janse van Rensburg have not been able to race together in the build-up to the Tour.

"This year we've all had to do different race programs," Renshaw said. "We've had a lot of trouble to get over this year. Hopefully we can get it right."

The bunch finish meant Greg Van Avermaet retained the yellow jersey, level on time with his BMC team-mate Tejay Van Garderen and three seconds ahead of Team Sky's Geraint Thomas.

Chris Froome and the rest of the contenders also finished in the main group to ensure the status quo held, with EF Education First-Drapac's Rigoberto Uran successfully chasing back on after being caught in a late crash to stay 10th, 35 seconds off Van Avermaet.

Four-time champion Froome sits in 17th place, 55 seconds down, in a battle for yellow still taking shape.

With the stage finishing in Sarzeau, where UCI president David Lappartient remains mayor, it seemed inevitable that his war of words with Team Sky boss Sir Dave Brailsford would continue.

On Sunday, Brailsford had accused Lappartient of not being presidential and having the "local French mayor kind of mentality", and Lappartient could not resist a retort of his own.

"By insulting me like that, he is insulting 35,000 mayors in France and the French in general," he told La Parisienne.

"I don't know what he is looking for. He does not understand much about cycling. He does not understand that it takes mayors taking stages of the Tour de France for such a great event to take place."

Lappartient then recalled that Brian Cookson had tried to use his role as a local mayor against him in last year's UCI presidential elections - and lost.

"When you are arrogant, one day or another there is always something that brings you back to humility," he said.

"I don't really want to answer him, but the last person who called me a Breton mayor didn't have much luck."