PRIME Minister Boris Johnson has laid flowers at the scene of the fatal stabbing of MP Sir David Amess, which police believe could be linked to Islamist extremism.

Mr Johnson, accompanied by Labour leader Sir Keir Starmer, Commons Speaker Sir Lindsay Hoyle and Home Secretary Priti Patel, laid a wreath at the front of Belfairs Methodist Church in Leigh-on-Sea, where Sir David was killed yesterday.

It came after Scotland Yard said the country's most senior counter-terror officer, Deputy Assistant Commissioner Dean Haydon, has formally declared the incident as terrorism and said early investigations have revealed "a potential motivation linked to Islamist extremism".

Sir David, 69, who had been an MP since 1983, was fatally injured while meeting constituents.

A 25-year-old man arrested at the scene on suspicion of murder is in custody at an Essex police station.

Official sources told the PA news agency the man is believed to be a British national with Somali heritage.

As part of the investigation, officers were also carrying out searches at two addresses in the London area, the Met said.