Brown pledges new action on terror laws when he takes over

Gordon Brown will tomorrow pledge to succeed where Tony Blair failed. In a key moment in the transition of power, the Chancellor will set out how he plans to win public backing for the fight against international terrorism with legislation to detain terror suspects without charge for up to 90 days.

Mr Brown will promise to create a "shared national purpose" based on "the British way" of improved accountability and judicial oversight. Once the public are reassured that judges and MPs are holding the police to account, they will support moves to extend detention without charge, he will say.

The Chancellor will also signal that MI5 and MI6, whose budget has already doubled to £2bn, are to be given still more cash in the forthcoming spending round. But he will concede that MPs should be handed independent scrutiny of the security services, something Mr Blair repeatedly refused to allow.

The Chancellor will promise, however, to carry forward the fight to allow police suspects to be detained beyond the current maximum of 28 days, insisting that police need the power to crack terror networks.

Labour MPs inflicted the first defeat on Mr Blair last November when they rebelled against plans to allow the police to hold suspects without charge for up to 90 days. But Mr Brown believes he can succeed in reviving the controversial measure.

"It may be possible that, in subsequent legislation, Parliament may be prepared to consider going beyond 28 days in circumstances where oversight is proven to work," he will say.

The speech is designed to place David Cameron under pressure ahead of a week dominated by anti-terror legislation.

The Government faces potential rebellions over ID cards on Monday, and over measures to ban the glorification of terrorism and the continuation of so-called "control orders" to monitor suspects on Wednesday.

However, on each issue, Mr Blair and Mr Brown believe they can succeed in portraying the new Tory leader as either "soft" or inconsistent.

Research carried out by Philip Gould, Mr Blair's private pollster, has convinced Labour's high command to make the issue of national security a key political battleground.

However, ministers face embarrassment over timescales as a Bill to introduce ID cards returns to the Commons tomorrow. One Government source said: "We are now talking about 2009; 2008 has definitely slipped back, partly because the legislation has taken so long."

Home Office officials have been warned privately that proposals to create a single national database to store data from the cards present a security risk, since, if hackers gained access, the whole system would be compromised.