Were you involved or were those in your office involved in decisions about the future of Jo Moore?

Iain Duncan Smith's letter to Tony Blair

The Conservatives are demanding an explanation after reports that Mr Blair personally intervened to save Ms Moore's career.

Mr Blair is said to have insisted Ms Moore stayed as he did not want the team of committed party activists Labour brought into government to be broken up.

Previously, Downing Street had given the impression that it disapproved of Mr Byers' decision to stand by Ms Moore, the Tories say.

The controversial special adviser finally quit her job last week along with her boss Martin Sixsmith after a series of leaks highlighted vicious in-fighting among officials in the transport department.

'Clear answer'

Pressure had been mounting on Ms Moore since details emerged of an e-mail she sent on 11 September last year - as the World Trade Centre burned - saying it would be a good day "to bury" bad news.

Jo Moore was dealt with under the disciplinary procedure of the department

The prime minister's spokesman

But according to the BBC's Political Editor Andrew Marr it was Mr Blair who stepped in to protect Ms Moore.

"Stephen Byers was quite willing to see Jo Moore go and then worried that it might set a worrying precedent and I think - fairly clearly - did get in touch with the prime minister and the message came back 'you hold on to her'," Mr Marr said.

Tory leader Iain Duncan Smith has written to Mr Blair demanding a response to this latest revelation.

In his letter, Mr Duncan Smith asks Mr Blair: "Were you involved or were those in your office involved in decisions about the future of Jo Moore?

"Did you or your office offer any recommendations to Mr Byers or his office over whether Jo Moore should be transferred or sacked from her post?"

Mr Duncan Smith renewed his call for a full inquiry into the affair.

Prime minister 'content'

Speaking on BBC Radio 4's The World at One, shadow cabinet office minister Tim Collins said: "At times, Downing Street has let it be known that perhaps Stephen Byers erred in keeping Ms Moore."

The prime minister's official spokesman said: "Jo Moore was dealt with under the disciplinary procedure of the department.

"The prime minister was informed of that and was perfectly content."

Questioned further by journalists, the spokesman would only say that he had said at the time that Mr Blair thought it was a very serious incident but not enough to finish someone's career.

He said the government believed in general that special advisors had a very valuable role to play.

Ten-point plan

Meanwhile, the Tories have drawn up a 10-point plan to protect the civil service from political interference.

They claim the proposals would address the "root causes" of recent controversies, including the Jo Moore/Martin Sixsmith affair and the row over Labour donor Lakshmi Mittal.

The proposals include the televising of Number 10's daily lobby briefing - where selected journalists quiz the prime minister's official spokesman.

Other proposals include:

• Statutory protection for civil service impartiality, with a cap on the number of political appointees

• Banning the abuse of power by political appointees, including revocation of the Order in Council which allows Mr Blair's communications chief Alastair Campbell and chief of staff Jonathan Powell to give orders to civil servants

• Drawing up legally-binding rules for special advisers to prevent "any further bullying and victimisation of civil servants"

• Requiring the prime minister to appear before the Commons public administration committee to account for the activities of his team

• The appointment of departmental permanent secretaries to be subject to the approval of the relevant Commons select committees

• A cull of "unaccountable czars and policy units"

• The ministerial code to be given legal force

• All official meetings and conversations involving ministers or senior civil servants to be properly and fully minuted

• Exploring the possibility of creating a commissioner who would have full access to both party and Government papers for the purposes of checking that party donations did not influence policy decisions

The Tories say the proposals should be included in a new Civil Service bill.