Great Northern trains running through Finsbury Park will continue south of King’s Cross from May, offering an alternative to the packed Northern Line for rush-hour commuters.

The service, operated by Thameslink, will begin to pass through new tunnels to St Pancras and join the cross-London line – creating quicker and direct journeys to Farringdon, City Thameslink and Blackfriars, before heading on to Brighton or Horsham via Gatwick.

The stretch between Finsbury Park and Blackfriars will have eight trains an hour, offering an alternative to the thousands of commuters who would otherwise be on the Northern Line.

The cutting-edge trains will tell passengers how the Tube is running and where to find seats on board.

Thameslink engineering director Gerry McFadden said it will transform thousands of lives. “We’ll be giving passengers longer trains and more services to provide vital added seats on a route that has seen a 70 per cent increase in passenger numbers in just 14 years,” he said.