More than one million people had signed a petition yesterday demanding Britain cancel plans for a state visit by US President Donald Trump following his ban on travellers from mainly Muslim countries.

With Prime Minister Theresa May under growing pressure over her ties to Trump, opposition MPs and members of her own Conservative party have also urged ministers to reconsider the visit later this year, which would see Trump honoured by parliament and Queen Elizabeth II.

But a Downing Street spokeswoman said: "We've extended the invitation. It's been accepted."

May announced the state visit during talks with Trump at the White House on Friday, intended to reaffirm the "special relationship" and boost trade ties after Britain leaves the European Union.

But her closeness to the erratic billionaire drew fire at home, particularly when she initially failed to condemn his ban on refugees and citizens from seven mainly Muslim countries.

A petition calling for the state visit to be cancelled because his "well-documented misogyny and vulgarity disqualifies him" from meeting the queen passed one million signatures yesterday morning.

Set up several months ago, the number of signatories has surged since Trump signed his executive order on Friday -- a move that triggered global protests, with more expected in Britain later yesterday.

"You are not welcome here, Mr President," headlined the Daily Mirror tabloid.

Opposition Labour leader Jeremy Corbyn, the smaller Liberal Democrats and the Scottish National Party have all called for the state visit to be cancelled, as have some Tories.

"We have to question whether ... this is something that Britain should be doing for a man who has no respect for women, disdain for minorities, little value for LGBT communities, no compassion for the vulnerable and whose policies are rooted in divisive rhetoric," Conservative Muslim peer Sayeeda Warsi told BBC radio.