Anti-war campaigners hoped on Monday to block the Number 10 switchboard and crash the government's email network.

The protesters, led by Body Shop founder Anita Roddick, mounted a "virtual march" on parliament and the government.

Drawing inspiration from peace activists in the United States, Roddick proposed that constituents should flood their MPs with emails and telephone calls expressing their concern about war in the Gulf.

Roddick argued that Tony Blair remains "infuriatingly unwilling to listen to the people" despite over a million demonstrators taking to London's streets last month to protest.

She believed that the "virtual march" would give people a further opportunity to register their "opposition to the wrongheaded rush to war".

Roddick praised the 121 Labour MPs who rebelled against Tony Blair's "hawkish stance" on Iraq.

But she argued that more needed to be done. "Let's jam Number 10 on the 10th," she said.

A similar protest in Washington last month saw more than a million callers jam phone lines on Capitol Hill.

The event also attracted a number of celebrity backers including veteran peace activists Martin Sheen and Susan Sarandon.