LONDON, Aug 25 (Reuters) - Illegal migrants found working in Britain will face jail and have their earnings seized under new measures announced by the government on Tuesday.

The government has been ramping up its anti-immigration rhetoric in response to a spike in migrant attempts to reach Britain via the Channel Tunnel in France and is under pressure to show it is acting to deal with the crisis.

Natacha Bouchart, mayor of the northern French port city of Calais where thousands of migrants are camped in the hope of crossing to Britain, has previously said Britain's generous welfare system and lax identity controls make it a magnet for illegal migrants.

"Anyone who thinks the UK is a soft touch should be in no doubt, if you are here illegally, we will take action to stop you from working, renting a flat, opening a bank account or driving a car," Immigration Minister James Brokenshire said.

"We will continue to crack down on abuse and build an immigration system that works in the best interests of the British people and those who play by the rules."

The government said it would introduce legislation when parliament returns from its summer break in September that would bring in a new offence of illegal working, carrying a jail term of up to six months and an unlimited fine. Wages earned by illegal immigrants will also be able to seized, it said.

Under the new measures, the government said it would also make it easier to prosecute employers who knowingly hire workers with no permission to work in Britain, and increase the maximum jail sentence to five years from two. (Reporting by Kylie MacLellan; Editing by Alison Williams)

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