PM vows to battle on over tuition fees as two more Labour MPs join the rebel camp

Tony Blair hinted yesterday that he might resign as Prime Minister if he loses the crucial Commons vote on university top-up fees this month.

He used his monthly press conference at Downing Street to increase the pressure on the rebel Labour MPs who are threatening to inflict a humiliating defeat on his flagship Higher Education Bill. He said: "The more the argument has gone on, the more people have seen that this is a bold reform, but also an important one and a right one. And there is no point in doing the job unless you carry these things through, and that's why we will do it."

He added: "You have to take a decision as Prime Minister about what the purpose of being in government is. And the purpose of being in government is to take difficult decisions which you believe to be in the interests of the country and to see them through."

The Prime Minister refused to be drawn on whether some of the Labour MPs opposing him over top-up fees were using the Bill as a pretext to attack his leadership. "It is not wise for me to get into speculating about people's motives," he said.

He predicted the Government would win the vote on 27 January but admitted there was still a "battle" to be fought and won. "Whatever the difficulties in the coming weeks, I believe we will win this argument. And I believe that as each day passes it is more obvious how important it is that we do win this argument for the future of this country," he said.

But Mr Blair suffered a setback when two more Labour MPs - Mohammed Sarwar and Andy Reed - joined the rebels by signing a Commons motion urging the Government to think again. This took the number of Labour signatories to 159, despite several "switchers" removing their names.

Defending his proposals for tuition fees as "necessary" and "fair", Mr Blair backed a plan to allow poorer students to be allowed to choose to bring forward £1,200 in discounted fee repayments after graduation to increase maintenance grants while they study. He said: "It may be that some of those students would prefer to take this money more in maintenance than in fee remission. It is possible to move towards a different system in the future."

Mr Blair denied that the proposal, to be outlined by the Education Secretary, Charles Clarke, on Monday, was being opposed by the Chancellor, Gordon Brown.

Mr Blair displayed figures showing that the state currently spends £5,300 a year on each university student. This compares with £4,300 for post-16 college students, £4,000 for secondary-school pupils, £3,200 for primary-age children and £1,800 for pre-school infants.

On Europe, Mr Blair played down fears that he would have to refight his battle to defend Britain's "red lines" when talks resume on the proposed European constitution. He insisted that progress made at last month's failed EU summit in Brussels would not be lost. "I would be quite surprised if the broad understanding that we had before was overturned."

On Northern Ireland, no political party with links to active paramilitary organisations could have any role in Northern Ireland's devolved government, Mr Blair said. He was "not satisfied" that the "acts of completion" needed to show that republicans had turned their backs on violence had taken place, but he believed the Sinn Fein leadership was committed to the peace process and called on them to end the "ambiguity" about republican intentions.

¿ Charles Clarke has ordered a cap on student recruitment to stop thousands of youngsters scrapping "gap years" to avoid paying top-up fees.

The Secretary of State for Education fears that up to 60,000 extra students will seek to start their courses 12 months early to avoid paying the proposed new fees.