Protesters campaigning against Brexit will march in Leeds next month to mark the one-year anniversary of the triggering of Article 50.
Leeds for Europe have dubbed the event the 'Great Northern March', which the group says will be one of the largest protest marches ever seen in Yorkshire.
The protest follows on from a Unite For Europe march in London in 2017 attended by 120,000, according to the group's own estimates.
A spokesman for the group said: "We are confident that this will be a fantastic event which will hopefully have a material impact on the Stop Brexit campaign.
"But to do this we need a vast number of peope to participate, which is going to take a massive effort to spread the word far and wide.
"Please start now to share this page with your friends, family, work colleagues, political contacts and anyone you meet.
"We are uniting the north of England for this event, and are expecting people to travel from across Yorkshire, Lancashire, the north east, the north west and the Midlands. In fact, this is intended to be an event of national significance."
Leeds voted Remain in the European referendum in 2016, while nationally, the vote swung in favour of Leave by 52% to 48% of those who voted.