London mayor has not been invited to the state banquet for Donald Trump when the president visits the UK in June.
Sadiq Khan, who recently reopened his feud with Trump saying the president was "not in same class" as previous presidents, is not on the guest list for the white-tie dinner hosted by the Queen at the Buckingham Palace.
Khan has said he did not want to go anyway.
Labour leader Jeremy Corbyn has also decided to boycott the dinner.
Saying he would be happy to meet with Trump, Corbyn said “maintaining an important relationship with the United States does not require the pomp and ceremony of a state visit.”
The Conservative government of prime minister Theresa May “should not be rolling out the red carpet for a state visit to honor a president who rips up vital international treaties, backs climate change denial and uses racist and misogynist rhetoric,” Corbyn said last month.
Khan, meanwhile, said Trump was not worthy of his upcoming state visit to Britain as he was not "in the same class" as his predecessors.
"History tells us only two presidents have had a state visit. I think President Trump is certainly not in the same class as those two."
Only George W. Bush and Barack Obama have been granted a state visit to the UK.
"Of course we should have a close relationship with the president of the USA, but we shouldn't be rolling out the red carpet, we shouldn't have a state banquet," added Khan.
Piyush Goyal and Jonathan Reynolds tour the Royal Opera House in London
