Thousands are set to protest outside Downing Street tomorrow if David Cameron attempts a “constitutional coup.”

The People’s Assembly Against Austerity called the action in anticipation that the Tories will try to cling to power against the will of most voters.

Within hours of the announcement, more than 4,500 people said they were planning to join the demonstration.

“The Tories and their mates in the media want to cling onto power even if they can’t get together a majority government,” said People’s Assembly national secretary Sam Fairbairn.

The protest plans were made after Tory supporters suggested that Mr Cameron should cling to power even if Labour and other left parties had more MPs.

Murdoch-owned newspaper The Times called on Monday for Mr Cameron to “occupy Downing Street” in the event of a hung Parliament.

But Mr Fairbairn predicted that thousands of people would turn out on the streets if the Tories attempted such a coup.

“The Tories had no clear mandate last time and still they went for the most vulnerable in society while the rich got richer,” he told the Star.

“Too many people will not survive another five years of a Tory led government. We won’t rest until they’re forced out of office by the people.”

Speakers at the protest will include journalist Owen Jones and comedian Mark Steel.

Parallel protests will also take place in Manchester, Newcastle and Bristol.

The action comes ahead of a national anti-austerity protest organised by the People’s Assembly on June 20.