Lord Birt to appear before MPs

Tony Blair's former 'blue skies thinker', Lord Birt, is to give evidence to MPs tomorrow – despite previous attempts by the prime minister to block such an inquiry.

The former BBC director general resigned as an unpaid advisor to Downing Street's strategy unit in December after six years working closely with the prime minister.

He will tomorrow be called before the powerful public administration select committee (PASC), as part of an inquiry into strategy and planning in government.

Previous attempts to get Lord Birt to appear before the MPs last year were blocked by No 10, prompting the committee to publicly rebuke the prime minister.

In a clearly worded report, the MPs said they were "disappointed" at Mr Blair's decision not to allow his own key advisors to appear before select committees, particularly given a reassurance by the government in the wake of the Hutton inquiry that they would.

Then leader of the House Peter Hain said in 2004 that "the committee's requests on attendance of civil servant witnesses, including special advisers, will be agreed to".

But the committee reported last November that "our experience suggests that this is not so", adding that its work was "hampered by an unwillingness to permit key advisers from No 10 Downing Street to give evidence".

Mr Blair was unrepentant, however, telling the Commons liaison committee later in that month that "I do try to be as helpful as possible", but that in this instance the acting director of the strategy unit, Stephen Aldridge, was better placed to speak to the PASC.

Lords committees have the power to force a peer such as Lord Birt to appear before them, but Commons committees do not have the same power.