Three Muslim men were yesterday accused of plotting a deadly copycat terror attack on Westminster.

The trio were allegedly secretly recorded discussing using explosives, guns, knives and vehicles for ‘mass murder’.

They are suspected of targeting key sites across London including Parliament, City banks, Heathrow and the Queen’s Guard.

Vast quantities of extremist material were said to have been found stashed on some of their phones, computers and a USB storage device.

Four men have appeared at Westminster Magistrates Court on terror and firearms charges

Police believe the alleged terror cell was inspired by Khalid Masood, who left four dead on Westminster Bridge before fatally stabbing a police officer in March.

Islamic scholar Umar Ahmed Haque, 24, Muhammad Abid, 26, and 18-year-old Abuthaher Mamun were arrested in raids across east London last week.

They appeared before Westminster magistrates’ court charged with offences under the Terrorism Acts 2000 and 2006.

A fourth man, Nadeem Ilyas Patel, 25, appeared alongside them charged with attempting to supply them with a firearm.

Kashif Malik, prosecuting, told the court: ‘The Crown’s allegation is that Haque was planning a terrorism attack in the UK involving mass murder.

‘He intended to use a heavy vehicle laden with explosives, he certainly had the know-how, as documented in the instruction manuals which have been recovered from his address, on how to make explosives. Or he was going to use a knife – and again manuals were recovered from his address on how to carry out knife attacks.

The four men were arrested in a series of raids by the Met Police's anti-terror unit this month

‘Or he was intending to use a firearm and we say he was trying to acquire one from Patel who was willing to provide one.

‘He shared his intentions with Abid in that conversation which was recorded, in which they glorified the attacks of Khalid Masood, the Westminster attacks and this demonstrates how their minds operate. They consider various other options and Abid said he would assist with the planning.

‘He also shared his intention with Mamun. In this conversation, which was also recorded, they talk about finances and what they would need to purchase – a gun or heavy vehicle.’

The men’s lawyers did not apply for bail and chief magistrate Emma Arbuthnot remanded them in custody to next appear at the Old Bailey on June 9.

The court heard Haque is accused of possessing a handwritten list of possible targets including government buildings, foreign embassies and tourist attractions.

At Patel’s home, police allegedly found two guns, one in the style of a Walther P99 pistol capable of firing gas pellets and a .22 air pistol.