Gordon Brown will announce today that he wants to find a British job for every British worker.

The move, which focuses on migration and nationality, is the Prime Minister’s latest attempt to outflank the Conservatives. He will announce incentives for employers and the long-term unemployed. He believes that they will encourage an extra 500,000 jobs to go to British workers, as well as confronting perceptions that foreigners are increasingly dominating the labour market.

Mr Brown’s decision to turn attention on immigration — a core Conservative subject — is also an attempt to unsettle David Cameron at the start of a week when the Tories will be focusing on the environment with the publication of a new policy review. In the past fortnight Mr Cameron has attempted to reassert his authority on hardline Tory issues, such as crime and immigration. This resulted in a narrowing of the poll lead with Labour and the departure of Johan Eliasch, his deputy treasurer, amid accusations of a lurch to the right.

Under Mr Brown’s plan, every teenager who leaves school in the summer would be offered a place on a preapprenticeship course or at college by the end of September. He will also announce a £400 training allowance for employers, an extension of benefits for single parents from 15 days to the first six weeks of work and an additional back-to-work credit of £40 a week, or £60 in London. He will look at how to get single parents and others who have not worked for some time into vacant jobs by aiming, for the first time, to guarantee a job interview for all those who apply.

Mr Brown will use his speech to union delegates in Brighton to announce tighter controls on would-be migrants working in Britain. Officials believe that the move could reduce arrivals by 35,000 a year.

The Prime Minister will say that skilled workers — such as IT programmers and engineers — coming from outside the EU must pass an English-language test. Since December only workers categorised as “highly skilled” — doctors and lawyers, for example — have had to show proficiency in English as a condition of entry.

The Home Office also announced yesterday a review of whether low-skilled migrants, who are not permitted residence in Britain, should also have to learn English.

The Prime Minister’s spokesman said that Mr Brown “believes that with jobs today available for more than 30 million people in the country, we can — if we make the decisions — advance closer to full employment than ever in our history, so that there is a British job for every British worker.”

Damian Green, the Tory immigration spokesman, said: “This will be a minor measure unless it leads to a cut in the numbers coming here.”

Nick Clegg, the Liberal Democrat spokesman, said: “What we need from the Government is a wider overhaul of our immigration system to make it both more efficient and fairer.”

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