http://www.bbc.com/news/uk-england-london-41572173

Transport for London (TfL) confirmed it was "temporarily pausing" plans to
buy more Jubilee and Northern line trains.

Improvements aimed to allow trains to run more frequently, TfL had said.
London Assembly Conservatives said a budget shortfall had led to the pause.

Leaders of the Aslef union said overcrowding would worsen and the delay may
force the project's "cancellation".

An additional 17 trains were to be bought so the Northern Line could run a
30 trains per hour service at peak times.

The Jubilee Line would have had 10 new trains to operate a 36 trains per
hour service.

Finn Brennan, Aslef's organiser on LU, said: "The Northern line is one of
the most overcrowded parts of the Underground and passenger demand is
projected to grow by a further 25% by 2023.
"Without new trains, overcrowding will get worse and worse."

The project had been paused due to a budget shortfall caused by Mayor of
London Sadiq Khan's flagship "fares freeze" policy., the assembly's Tories
claim.
Member Keith Prince said the freeze "blew a £640m hole in TfL's budget."