Deputy Prime Minister John Prescott was quick to react after a purple flour bomb bounced off Tony Blair's shoulder and exploded in the Commons yesterday.

Throwing his order papers to the floor - he used to be a barman on a ship - Mr Prescott had the mess covered in no time.

But no one on the Government front bench tried to dive in front of the missile when it was in mid-flight.

In days gone by, it would have been possible to imagine a loyal Cabinet minister leaping into its path, shouting: "No, not Tony - take me!" Now they don't have the energy or, perhaps, the inclination.

As the dust settled, most MPs remained calm amid the chaos. Former Tory leader Iain Duncan Smith, an Army veteran, was typically sensible.

He said: "I was sitting still, telling people to stay put. If it had been a chemical or biological agent, which it was not, what we did would successfully have spread it around London.

"With a threat like this, you should seal the doors."

It took just 39 minutes for Home Secretary David Blunkett to decide the outrage would lead to severe new restrictions on public access to the Commons.

He called an impromptu Press conference at the Police Federation in Bournemouth, which he was attending at the time.

As virtually the only senior politician not in the chamber, had the powder been anthrax he could have been speaking as the newly-appointed Prime Minister of a one-party state.