MPs are due to debate US President Donald Trump’s state visit to the UK, amid protests against the trip.
It comes after two petitions received more than the 100,000 signatures required for such a debate to be considered in Parliament.
A petition against the state visit got 1.85m signatures, while one supporting it got 311,000.
Campaigners will protest against the “hatred, racism and division that Donald Trump is trying to create”.
Prime Minister Theresa May announced the state visit during a visit to Washington for talks with Mr Trump.
The debate at Westminster Hall on Monday evening will be opened by petitions committee member MP Paul Flynn, with a response by Foreign Office minister Alan Duncan for the government.
The petitions were titled Prevent Donald Trump from making a State Visit to the United Kingdom (1.85 million signatures) and Donald Trump should make a State Visit to the United Kingdom (311,000).
Campaigners from the Stop Trump Coalition will gather for a rally in Parliament Square while the debate is taking place.
Similar demonstrations will be held elsewhere around the UK, including in Edinburgh, Manchester, Liverpool, Cardiff and Newcastle.
Campaigners are also marking “One Day Without Us”, celebrating the contribution of migrants to the UK, coinciding with the United Nations’ World Day of Social Justice.
London Mayor Sadiq Khan has said that Mr Trump’s “cruel and shameful” policies mean he should not be granted a state visit.
Tory MP Sir Nicholas Soames defended the invitation, saying it would be “controversial but important”.
Commons Speaker John Bercow was criticised by some MPs after he said Mr Trump should not address Parliament during the trip in light of the row over his travel ban and comments about women.
Mr Trump was invited to the UK for a state visit after just seven days as president, while it took 758 days for Barack Obama and 978 days for George W Bush.
The government has said it recognised the “strong views” expressed by the US president but looked forward to welcoming him once details have been arranged.