A radical reduction in class sizes is needed to solve the crisis in our schools, a former top advisor to Tony Blair warned.

Cutting infant classes to 15 or 20 children would give all pupils a fairer start in life, said Matthew Taylor, director of the Institute for Public Policy Research.

Speaking in Brighton after The Argus revealed one Sussex school is so overcrowded that governors are worried about children's safety, Mr Taylor said the Government's policy of reducing infant class sizes from 32 to 30 made no difference at all.

He said Labour's key election pledge to reduce class sizes in the inner cities to 30 was wrong.

Instead the party should have promised to cut classes to 15, the same as the private school average. Research in the US showed radically cutting class sizes worked.

He said: "I think the Government made a mistake in 1997 and that was the class size pledge.

"Reducing class sizes from 32 to 30 makes no difference at all. Nonetheless, I think the money should have gone to the schools with the worst problems and should have massively reduced class sizes to those of the independent sector.

"I would like to see these reductions in all inner city schools."

Yesterday The Argus revealed how governors at Balfour Junior School warned the school is so full they fear pupils safety could be at risk.

The Leadership of Independent School Conference at Brighton College, attended by 250 independent school heads, debated how to deliver all round education excellence.

Mr Taylor told them: "The more the independent sector expands, the more damage is done to the state sector.

"We are talking about a real crisis about the capacity of the state sector to succeed when it is increasingly providing for a group which excludes the self-confident and educationally more able."