From the story in the Times:

Plans by al-Qaeda terrorists to crash aircraft into Canary Wharf and at Heathrow have been thwarted by the security services, it was claimed last night.

Pilots would have been trained for suicide missions in strikes modelled on the September 11, 2001, attacks in the United States, according to a report on ITV News. But the claims were greeted with scepticism, given their timing on the eve of the Queen's Speech, which will outline a legislative programme dominated by Bills to tackle terrorism, organised crime and disorder.

This was the lead story in the Express and the Mail today, but without any mention of the scepticism.

See also:
http://www.theregister.co.uk/2004/11/23/terror_scare_spin/.