Watergate journalist's new book exposes how Bush has kept the US public in the dark about the true costs of the 'war on terror'

President George Bush was braced for one of the toughest fights of his political life yesterday as a fierce row broke out over whether he has been misleading the American public over the worsening violence in Iraq. The crisis also rippled across the Atlantic with claims that the administration hid crucial Iraq intelligence from its British allies.

Sparking the crisis was a series of leaks from a hard-hitting new book by the political journalist Bob Woodward, one of the two Washington Post reporters who broke the Watergate scandal that engulfed the Nixon administration three decades ago.

The author's first television interview on the Iraq book is due to be shown this evening on the CBS show 60 Minutes, and is expected to ignite a huge row over the conduct of the war. The book lifts the lid on an administration in crisis, claiming that Bush and his top officials have deliberately covered up the seriousness of the violence in the war-torn country.

Woodward has so far been sympathetic to the Bush administration's decision to go to war in Iraq.

In the TV interview Woodward accuses Bush of keeping the real situation in Iraq secret from the American public and playing down the true level of violence. 'There's public [information] and there's private. But what did they do with the private? They stamp it secret. No one is supposed to know,' he says.

His book - State of Denial - is also understood to say Tony Blair was angry at discovering that Washington was keeping key intelligence on Iraq from Britain - even classifying reports based partly on contributions from British operatives as off-limits. In some cases, British personnel flying US planes in Iraq were denied access to pilots' manuals, the book reportedly alleges. Downing Street denied to comment last night.

Woodward's book says that insurgent attacks in Iraq are now running at a rate of about four an hour and that officials believe the situation will get worse next year. That allegation is particularly damaging to the administration, which has staked its reputation in mid-term Congressional elections on its ability to win the war. It also flies in the face of regular Republican claims that the situation in Iraq is improving.

Woodward's book also provides a gripping insider's account of a White House deeply divided over Iraq. It shows that Secretary of State Condoleezza Rice has been at odds with Bush over the war and that former White House chief of staff Andy Card had backed the replacement of Defence Secretary Donald Rumsfeld - but was overruled.

It portrays Bush as determined to stick it out even if his only supporters are whittled down to his wife and the White House dog. 'I will not withdraw, even if Laura and Barney are the only ones supporting me,' Woodward quotes Bush as having told top Republicans at a White House meeting.

The book could not have come at a worse time for the Republican party. America is gearing up for vital elections and both parties are fighting on the issue of national security. That is usually a Republican strength, but Woodward's book will undermine the idea that the ruling party is best at prosecuting the war.

Bush spokesman Tony Snow has denied one key allegation - that Rumsfeld no longer takes calls from Rice. 'That is ridiculous,' Snow said. The White House has also insisted that the war in Iraq remains a vital part of the wider war on terror. In his weekly radio address, Bush said that fighting Islamic militants was part of winning the struggle against terrorists.

He also slammed Democrats and others who used a leaked intelligence report last week - which warned that invading Iraq had made America more prone to terrorist attack - to score political points against Bush's Iraq policy. 'Some in Washington have selectively quoted from this document to make the case that, by fighting the terrorists in Iraq, we are making our people less secure here at home. This argument buys into the enemy's propaganda.'

But it is now far from clear that such arguments are resonating with the American public.

The Democrats, who once shied away from any debate on national security, have started to make it the central plank of their mid-term campaign. The party pulled no punches yesterday in responding to Bush's radio speech by choosing the Democratic Congressional candidate Tammy Duckworth to give its official response. Duckworth is a helicopter pilot who lost both legs in Iraq and now is a candidate for a seat in Illinois.

She vigorously attacked Republican attempts to paint her party as 'cutting and running' from the war. 'I believe the brave men and women who are serving in Iraq today, their families and the American people, deserve more than the same empty slogans and political name-calling,' Duckworth said.