Hundreds of thousands of activists are preparing to paralyse London with mass demonstrations during Donald Trump's state visit next week.

More than 20,000 police officers will be deployed at 20 separate events planned across the country in a security operation expected to cost about £18million.

The main protest will be held in central London on Tuesday with organisers claiming a quarter of a million will march from Trafalgar Square to Parliament Square. Scotland Yard has given them permission to protest just yards from Downing Street while the US President has lunch there with Prime Minister Theresa May.

Two groups – Stand Up To Trump and Stop Trump – are co-ordinating protest groups for what they are calling a 'carnival of resistance'. They have laid on coaches to bring thousands of supporters to the capital from cities and towns across the UK.

A spokesman for Stand Up To Trump said: 'We will be bringing central London to a standstill. By the time he leaves he will know, and the world will know, that people here reject him and his toxic politics.'