The Government is to spend an extra £3bn on public sector infrastructure projects – but not until 2015 and at the expense of cuts to other areas of spending.
The money is expected be concentrated on big transport projects including road schemes in Scotland and Wales and further investment in the railway network, although Mr Osborne said he would announce where it would be allocated in the Comprehensive Spending Review in June.
The new money takes the total spending on infrastructure projects to £18bn over this Parliament.
An update on 40 high-profile projects under the National Infrastructure Programme showed that just two of the schemes were due for completion in 2013 while a number appear to be significantly behind schedule.
In a tacit acknowledgement of the difficulties faced in getting the projects off the ground, Mr Osborne said the Government would hire a central unit of commercial specialists to oversee large scale projects.
He said: "We're already supporting the largest programme of investment in our railways since Victorian times – and spending more on new roads than in a generation." He also highlighted the effect of Treasury guarantees of major projects.