the government has defended its pound;45 billion school building programme but admits it needs to be better at learning from past mistakes if it is to get the initiative back on track.

Jim Knight, the schools minister, launched the defence following the revelation this week that of the 300 new schools scheduled to open by the end of next year, fewer than 70 will actually be finished.

It was the latest setback to the Building Schools for the Future programme, which aims to rebuild or refurbish all secondary schools over the next 15 years, after officials were forced to admit that there was a worrying lack of expertise to deliver the project.

Mr Knight said: “This programme will only be a success if we learn from what is already working. We must be smarter about sharing experience, and local authorities must have the help they need to deliver the projects.”

Speaking yesterday at Arsenal’s impressive new Emirates Stadium - the building came in on time and on budget - Mr Knight said the Government was putting pound;6bn into schools capital this year compared to pound;700 million in 1997.

“But this is not just about spending money. It is about improving education for all our children,” he said. “I make no apologies for making sure we get this right - these schools must be built to last. The process of planning, financing, designing and building is complex. It will take time.”

Sally Brooks, head of schools capital at the Department for Education and Skills, told the Commons Education Committee last month that local authorities were struggling to deal with the size of the programme.

Mr Knight yesterday promised pound;2m in additional funding over the next two years to help authorities deal with the design process. The money will go to the Commission for Architecture and the Built Environment to establish a new school designs assessment panel, which will assess proposals to ensure high quality buildings.

The National College for School Leadership will also provide courses for authorities and school leaders to help maximise the impact of the building programme.

Mr Knight defended work that had already taken place. “We’ve removed decaying temporary classrooms, repaired leaking roofs, installed efficient heating systems and improved security,” he said.

“Those that knock our investment are attacking change that will help millions of pupils. Ultimately, we will all be judged on positive impact, not good intentions.”