The building of London's Olympics venues will face a skills shortage because too few Londoners were being trained as builders, the Tories claimed today.

Shadow universities minister David Willetts said there was a danger that thousands of skilled Polish plumbers, bricklayers and construction workers would go home before the 2012 games.

He said 2012 was also the year for Poland to host the European Football Championships, adding: "They are busy planning new stadiums and arenas and expect many of their workers to return to help build them."

There are believed to be more than one million Polish citizens in the UK, almost all of whom have come for work in the wake of the expansion of the European Union in 2004.

Mr Willetts said only 62 apprentices were currently learning building skills on the London Olympics workforce, too few to make a difference.

"What a wasted opportunity," he said. "We can do better. And we will." He announced a £20 million programme of scholarships for 1,200 young apprentices to go to university.

Those expected to take advantage of the scheme would be working mainly in science, technology, engineering and mathematics - specialties in which undergraduates are falling.

Mr Willetts said: "Many young people find themselves and discover their self-confidence when they master a skill. But they should be able to go on studying afterwards when they might gain even more.

"If you start as an apprentice phone engineer and show a real aptitude for the academic side too, surely you should have the chance to go on and study electrical engineering at university."

Mr Willetts promised that all tuition costs would be covered by the bursary, adding: "This will create a robust, accessible vocational pathway to higher learning for the first time."