Prime Minister Tony Blair's election campaign plane has been struck by lightning during a flight.
Tony Blair visited a school in Bolton, before returning to London
BBC Radio Five Live presenter Peter Allen, who was on board, said it was hit as it approached London. The plane was not damaged and landed safely.
Mr Allen said he heard a loud bang but the prime minister, who was talking to a journalist at the time, was apparently "imperturbable".
"The rest of us certainly weren't imperturbable," Mr Allen said.
'Red and white flash'
BBC producer Will Walden said many of the journalists were asleep when the incident happened over London at about 1400 BST.
"All I remember was a red and white flash just in my mind which woke me up with a start," he said.
"The plane wobbled from side to side but it was also quite rough anyway because it was pretty cloudy and rainy. Lots of people looked momentarily shocked."
One journalist was talking privately to Mr Blair and when she suggested the lightning strike could have been a missile, the Labour leader just shrugged his shoulders and "didn't bat an eyelid".
The pilot did not make a tannoy announcement about the incident and the plane landed safely at Heathrow airport about 10 minutes later.
After landing, the pilot explained such strikes were reasonably common and the plane's wings contained conductors to dissipate the electricity from a lightning.
Mr Blair's plane has been hit by lightning before, during a trip to Washington.
Conservative leader Michael Howard also had a brush with stormy conditions on Wednesday.
Forced to abandon his helicopter because of engine problems, Mr Howard took a commercial flight.
At one point the flight's pilot announced that the "pop" that passengers might have heard was a lightning strike 15 miles away.