Gary Lineker and Lily Cole will be among more than 1,000 people standing in solidarity with refugee children.
Around 1,200 are expected to join the Love In Action Have a Heart demo, gathering at the Millennium Bridge in London on Wednesday morning, to symbolise the 1,200 unaccompanied child refugees living in Calais Jungle.
Campaigners want to put pressure on the government to help those stranded in the Jungle.
They will call on it to accelerate its implementation of the Dubs amendment - something that enables unaccompanied children to be offered safe refuge in Britain - so the refugees can escape before the camp is demolished.
Lineker's appearance at the event comes after he received "a bit of a spanking" for saying the treatment of young migrants arriving in the UK was "hideously racist".