PARIS (REUTERS) - Thousands of French restaurants serving up mass-produced "boeuf bourguignon" and potato "gratin" as if lovingly prepared from scratch by their own chefs may soon be exposed by law.

In a country that takes pride in its culinary reputation, parliament voted for a law on Thursday that would force restaurants to identify meals prepared on their premises with a "homemade" label, showing that any other items are likely to have been brought in and simply warmed up.

Any restaurant misusing the label on their menus would be fined.

The draft law aims to expose eateries that buy ready-made meals in bulk and heat them up in the microwave. It also addresses concerns about food standards after a Europe-wide scandal over horsemeat found in ready meals such as beef lasagne.

The bill, that passed easily through the lower house, now goes to the Senate, which is likely to debate it in September.

It has strong backing among upper-end restaurants and overwhelming support among the public, surveys show.

Supporters say the law could rescue French cuisine and create jobs by nudging restaurants back towards cooking fresh food on their own premises.

"We're making things more transparent and restoring our trade's respectability," said Mr Didier Chenet, head of restaurant federation Synhorcat.

"Clients will know what to expect. The problem right now is that you push the door of a restaurant and you don't know if there's actually a chef in the kitchen," he told Reuters.

A survey by Synhorcat found that 31 per cent of French restaurants admitted to using at least some ready-made dishes.

Among those, two-thirds said that if a label forced them to confess the practice to clients they would cook fresh produce on their premises instead.

The switch could create around 25,000 jobs in the kitchens of France's 120,000 restaurants but would result in a 7 per cent price hike, Synhorcat said.