The focus of demands to allow more child refugees into Britain will be shifted to Downing Street when a mass petition is handed in to Number 10.
Labour peer Alf Dubs is delivering the 50,000-signature petition to the Prime Minister's residence on Saturday, following widespread criticism of the Government's decision to close an initiative to let unaccompanied children into the country.
A Parliamentary move, branded the Dubs Amendment because it was championed by Lord Dubs, was expected by its backers to bring in some 3,000 refugee children, but is being shut down by ministers after 150 youngsters joined the 200 already accepted into the UK.
Religious leaders are expected to join Lord Dubs in his petition presentation after the Archbishop of Canterbury warned that halting the initiative would see more children being trafficked, exploited and killed.
The Most Rev Justin Welby intervened in the heated political row, saying he was "saddened and shocked" at the move.
He said it would be "deeply unjust" to leave the burden of caring for such children on Italy and Greece, where thousands of refugees and migrants arrive from the conflict-ridden Middle East and north Africa.
Home Secretary Amber Rudd said British and French authorities were concerned the scheme was acting as a "pull factor" for children to be drawn to the UK and that it provided opportunities for people-traffickers.
More than 900 unaccompanied children were transferred to the UK from Europe last year.