English Defence League (EDL) supporters shout at anti fascist protestors during a rally outside Downing Street, London on May 27, 2013 Peter Macdiarmid/Getty Images

Far-right EDL and Britain First protesters are to be faced by anti-fascist groups at a demonstration planned in central London on Saturday, following the Westminster terror attack.

In a Facebook post, the London Anti-Fascist Network called on supporters to gather in Trafalgar Square at midday on 1 April, to "crush the fascists' attempt to cynically grow off the death of ordinary Londoners".

On Wednesday, 22 March, Khalid Masood drove a vehicle at 76mph along Westminster Bridge, killing three pedestrians. He crashed the vehicle and got out, stabbing a police officer to death before being shot dead by police outside Parliament. Hours afterwards, former EDL leader Tommy Robinson was at the scene of the attacks denouncing Islam.

Shortly afterwards the EDL and radical anti-Islam group Britain First announced plans to meet at Trafalgar Square on 1 April, before marching with flags and banners along Whitehall and gathering for a rally in Parliament Square.

Both groups have held anti-Islam demonstrations in cities across Britain in recent years.

In its statement, the London Anti-Fascist Network called for supporters to "stand together and not let them divide us". 276 people on the page have expressed their intention to attend the counter-demonstration.

The network declares its mission on its website as being to "confront and disrupt any level of fascist organisation to the greatest extent of our capabilities", and is a member of the militant Anti-Fascist Action network. Members have violently clashed with far-right supporters in previous protests.

In 2013, there were 160 arrests when EDL supporters clashed with counter-demonstrators at a protest in Tower Hamlets, east London, home to one of London's largest Muslim communities.

A Metropolitan Police spokesman said the force was not commenting on the planned protest.