David Cameron 'texted Rebekah Brooks before she resigned over Dowler affair'

New biography throws spotlight on closeness of relationship between PM and former Sun editor

David Cameron privately sent Rebekah Brooks a message of support as his government was publicly condemning her newspaper group for hacking Milly Dowler's phone, it emerged last night.

In the week before she resigned as chief executive of News International over the targeting of the missing schoolgirl, the Prime Minister texted Mrs Brooks last July to tell her to keep her head up and that she would "get through" her difficulties, according to a new biography of the Conservative leader.

Days later the Prime Minister sent an emissary to explain to Mrs Brooks that he could not back her publicly because of the political pressure caused by the scandal, according to authors Francis Elliot of The Times and James Hanning, deputy editor of The Independent on Sunday.

In the updated biography, Cameron: Practically a Conservative, they lay bare the closeness of the relationship between Mr Cameron and Mrs Brooks, confirming that despite the misgivings of some senior Tories, they would regularly "pop round to one another's houses" in south Oxfordshire. The relationship bore fruit politically, with all of News International's newspapers, The Sun, Times, Sunday Times and News of the World endorsing the Conservatives at the 2010 general election.

Referring to the regular visits between the two, the authors write in the book, serialised in The Times today: "The wider public might have liked to know too of the text message that [Mrs Brooks's husband] Charlie Brooks told friends Cameron sent to Brooks at the beginning of the week in which she resigned, telling her to keep her head up and she'd get through her difficulties. Such contact came to an abrupt halt soon afterwards, with Brooks not wanting to embarrass Cameron and he wanting to be able to say, hand on heart, that they had not been in touch.

"But it was claimed that Cameron did send an emissary to Brooks to mitigate his sudden coldness towards her. The gist of the message was, 'Sorry I couldn't have been as loyal to you as you have been to me, but Ed Miliband had me on the run'."

Of Mrs Brooks – who was later arrested on suspicion of phone hacking, corruption and conspiracy to pervert the course of justice – the Conservative frontbencher Oliver Letwin said: "If you are on the same side as her, you have to see her every week. This was how it worked. It was what was demanded if you wanted them on your side."

He told the authors: "All of us should have said, 'We'll have nothing to do with them and we'll only meet them when we absolutely have to'. But the problem with that is if the other guy is doing it... That game is over, thank God."

Downing Street is said to be nervous about the evidence Mrs Brooks gives on Friday at the Leveson Inquiry into press ethics, amid speculation that it will include text messages between her and the Prime Minister.

Another tough day for the Government looms tomorrow when the inquiry hears from Mr Cameron's former director of communications, Andy Coulson. Mr Coulson was taken on by Mr Cameron months after he resigned as editor of the News of the World in January 2007 over the jailing of a journalist for hacking the phones of royal aides. According to the new book, aides warned Mr Cameron against taking Mr Coulson into Downing Street after the 2010 election.

* An emergency appeal asking for "partisan" Government advisers not to be given advance access to key witness statements and documents at the Leveson Inquiry will be considered by Lord Justice Leveson.

This week, with the inquiry hearing potentially controversial evidence from both the former editor of the News of the World, Andy Coulson, and News International's former chief executive, Rebekah Brooks, a group of civil rights lobby groups has demanded that so-called "spads", or special advisers, should not have the right to see, alter or redact witness statements.

Lord Justice Leveson was expected to announce his decision at the start of today's hearing.

Coulson wins legal aid appeal

Andy Coulson kicked off a busy week yesterday. In Court 71 of the High Court he won the right to an appeal relating to his legal bills. On Friday, he'll be back – in Court 73 at the Leveson Inquiry. Looking relaxed, he told The Independent the legal process was "a long journey" that still had some way to go.