LONDON — Thousands of protesters rallied outside parliament on Monday as MPs debated a petition to cancel a state visit by US President Donald Trump which gained more than 1.8 million signatures.

Placards reading "No to Trump" and "Dump Trump" were held by demonstrators in Parliament Square, in the latest rally against the US president who came to power a month ago.

British Prime Minister Theresa May became the first foreign leader to meet Trump in the White House in January, when she invited him to the UK on a state visit to be hosted by Queen Elizabeth II later this year.

The invitation came hours ahead of Trump imposing tough entry restrictions on travellers from seven Muslim-majority countries and within days an online petition to prevent the president’s state visit attracted more than 1.8 million signatures.

The British government has said it will not support the petition and stressed that the invitation still stands, but parliament went ahead and debated the issue due to the popularity of the petition.

Lawmakers also discussed a counter-petition to uphold the state visit invite, which attracted over 300,000 signatures.

During the debate, opposition Labour MP David Lammy said the government offered the state visit because it is "desperate" for a trade deal with the US.

"I think my children deserve better than that... I’m ashamed that it’s come to this," he said.

Fellow Labour lawmaker Paul Flynn said the invitation should be downgraded from the regal affair to a regular visit.

"There are great dangers in attempting to give him the best accolade we can give anyone," he said.

While Trump was offered a state visit after just seven days in office, his predecessor Barack Obama had to wait 758 days before receiving the same invitation.

Outside parliament on Monday, protester Benjamin Kari said people needed to stand up against Trump’s policies and avoid becoming complacent.

"He’s promoting racist policies, he’s normalising racism and misogyny and Islamophobia," he said.

Bryan Richardson, a member of the Stand up to Racism group, said May "humiliated herself by rushing over to Washington to be the first leader to meet Donald Trump".

A Stop Trump Coalition website named February 20 a "day of action" against the US president, listing events planned across Britain.

Around 300 people gathered in Glasgow waving sometimes comical banners aimed at Trump, one describing him as a "Feckin Plonker". — AFP