Britain must start preparing for the eventual economic upturn, the Prime Minister said today as he set out ambitious plans to improve the chances of the most disadvantaged in society.

The Government's New Opportunities White Paper on social mobility included an offer of £10,000 "golden handcuffs" payments to the best teachers who were prepared to work at the worst performing secondary schools.

The deal forms a key plank of the proposals, alongside an extension of free nursery and childcare places to 15% of the most disadvantaged families with two-year-olds.

It follows research indicating that children in Britain are less likely than those in other developed countries to move up the social ladder and get better jobs than their parents.

Launching the White Paper, Gordon Brown said he wanted to ensure that everyone was able to take advantage of the eventual economic recovery when it comes.

While he acknowledged that the coming months would be "tough", he said the global economy would return to growth in the years ahead, creating up to 1 billion skilled jobs worldwide.

"During this global economic downturn we must continue to invest in people so they have a fair chance to achieve their potential," he said.

"The world economy is set to double and the expansion of digital and green industries will offer new opportunities. We must be ready to seize these opportunities and ensure that these better jobs can be captured by everyone."