Blair scuppers Brown's hopes of an early handover

Tony Blair has signalled that he intends to scupper Gordon Brown's hopes of taking over as Prime Minister by mid-June.

In a further sign of tension between the Prime Minister and his likely successor, Mr Blair warned Labour could lose the next election unless it turned itself into "New, New Labour". Speaking at his monthly press conference, Mr Blair was asked whether he intended to attend the summit of European Union leaders on 21 June. "Of course," he replied, without hesitation.

Mr Brown wants to succeed Mr Blair by mid-June, which would give him about six weeks to launch his premiership before Parliament starts its summer break and much of the country switches off from politics during the holiday season.

Mr Blair is expected to disclose his departure timetable before the May elections to the Scottish Parliament, Welsh Assembly and English local authorities, in the hope of limiting Labour's losses. But he seems determined to attend G8 and EU summits in June before leaving Downing Street.

The Prime Minister also endorsed a warning by David Miliband, the Environment Secretary, that Labour will have to "defy political gravity" to win a fourth consecutive election. Mr Miliband, a Blairite who is backing Mr Brown as the next Labour leader and is resisting pressure to run for the job, called for "bold" reforms and warned that "continuity" with the Blair era would not be enough.

Asked about public disillusionment with Labour, Mr Blair said: "I believe that provided we hold our nerve and the reform and change programme, provided we go to New, New Labour if you like, and don't retreat from New Labour, we will come through this."

Some Labour MPs hope Mr Blair can be persuaded to quit before June.