HARDtalk - Frank Field MP, Labour backbencher

The Prime Minister, Gordon Brown, is facing one of his most serious tests of authority since coming to power. Around forty Labour MPs have signed an amendment to the finance bill challenging his decision to abolish the 10p income tax band. With Mr Brown's 67 strong Commons majority on a knife edge, there are growing concerns about whether the Government could survive defeat on such a key Budget measure. Frank Field is leading the rebellion. He talks to Stephen Sackur.