Jeremy Corbyn has compared Theresa May's Brexit deal to "Frankenstein's monster" as the prime minister faced pressure on all sides ahead of a crunch Commons vote.

As MPs returned to Westminster after the Christmas break, rival Brexit factions turned up the heat on Ms May over her blueprint, which is expected to be voted down in a parliamentary showdown on January 15.

The Labour leader said there could be "no more hiding and no more running away" from holding the long-promised meaningful vote on Ms May's deal, with only three months left until exit day.

He accused ministers of pushing a "Frankenstein's monster of a deal" and criticised "shambolic" no-deal Brexit preparations by transport secretary Chris Grayling.

His comments came as the government faced ridicule over its first major tests of plans for no-deal chaos at UK borders, when scores of lorries travelled from Manston Airport, near Ramsgate, in Kent, to Dover, to trial contingency plans to ease congestion on the roads and at ports.