The Prime Minister had to rely on Tory support to get his Bill through its first Commons vote but the sky did not fall in.

However, many Labour backbenchers who had threatened to rebel only relented on the understanding that the Government would “clarifiy” their remaining areas of concern.

The MPs want to know exactly what criteria the new admissions code will be based on; the circumstances under which the Education Secretary will veto new community schools; and how the process allowing external organisations to run schools will be regulated.

If ministers fail to give reassurance on these points they could find the original 52 Labour rebels joined by as many as 70 more when the next full Commons vote takes place at the end of May.

Meanwhile opinion polls suggest the reform proposals may have led to a sharp fall in the percentage of teachers satisfied with the Government’s performance.

According to Mori the satisfaction rating has dropped from a high of 38 per cent in Spring 2004 to 31 per cent in the month that followed the launch of the education white paper on October 25.

Worringly for ministers, satisfaction is lowest among older teachers - the middle and senior managers they will be relying on to implement many of the reforms.

Overall, 52 per cent of teachers with more than 11 years’ experience were dissatisfied with government performance on education, compared with 36 per cent of those with up to a decade in the job.

Leading Labour backbenchers originally said the Government had agreed to address the three outstanding issues during the committee stage of the Bill. But one, Angela Eagle, twin sister of Maria Eagle the children’s minister, has now told The TES that they may not get the answers they are after until the report stage of the Bill.

Whenever it happens the risk for Mr Blair is that any further concession will give the Conservatives an excuse to withdraw their support, leaving him facing defeat at the hands of more than 50 hard-core Labour rebels.