The government said on Wednesday it will keep restrictions on the number of Romanians and Bulgarians allowed to work in Britain until the end of 2013 to avoid harming the jobs market at a time when unemployment is at a 15-year high.

The decision means Britain will maintain restrictions on Romanian and Bulgarian workers for the maximum seven-year period allowed under European Union rules. It will be forced to lift them at the end of 2013.

Maintaining these controls will make sure migration benefits the UK and does not adversely impact on our labour market, Immigration Minister Damian Green said in a statement.

The British rules, in force since Romania and Bulgaria joined the EU at the beginning of 2007, restrict people from those countries to applying for skilled jobs or for jobs in sectors where there is a shortage of labour.

Around 25,000 Bulgarian and Romanian workers may also work in Britain each year in agriculture and food manufacturing.

EU members are allowed to limit the inflow of Bulgarian and Romanian workers until December 31, 2011, and for a further two years if lifting the restriction would cause a serious disturbance to the labour market.

Green said he had sought advice from an independent Migration Advisory Committee, which had concluded that the British labour market was currently in a state of serious disturbance and that lifting the current restrictions at this stage would risk negative impacts on the labour market.

Britain had previously said it was imposing the restrictions until the end of 2011.

Data released last week showed unemployment hitting its highest in 15 years as Britain struggles to recover from a deep recession. Joblessness among the young has soared to a record of more than one million, adding to pressure on the government to do more to support the faltering economy.

Britain's 18-month-old coalition government plans tougher curbs on immigration to cut the number of people the country absorbs from more than 200,000 a year to tens of thousands.

Britain was one of three EU members, along with Sweden and Ireland, that granted open access to workers from a first group of eight central and east European countries that joined the bloc in 2004.

The then Labour government sharply under-estimated the number of workers who would come to Britain from those countries. A thinktank said in 2008 that one million immigrants from eastern Europe had arrived in Britain since 2004 but half had returned home.

High immigration has fuelled resentment among some Britons that foreign workers are undercutting wage rates and beating British workers to jobs. However, employers say British workers are unwilling to do some jobs.

The coalition, critical of Labour's record on immigration, has said it will always impose temporary restrictions on workers from countries that join the EU in future.

(Reporting by Adrian Croft)