Rail union RMT has spoken of a 'crisis' on the Piccadilly Line thanks to train shortages as up to 17 trains are reportedly out of action.

The union claims that the trains are out of action due to worn running gear that pose a danger for passengers and staff if they were in operation.

The Piccadilly Line is London Underground's fourth busiest line, transporting an average of 600,000 people a day and has recently seen delays during rush hour in the mornings.

The union claims the issue of worn brakes and other faults on the trains has been raised.

RMT General Secretary Mick Cash said: “This was a crisis that we said was coming and is wholly down to a lack of investment and corner-cutting to try and cover up the facts.

“RMT will continue to force the pace on this issue which has safety right at its heart. We have also made it clear that any blaming of staff for this rolling stock crisis will be met with the strongest possible response”

Talks are currently underway between union representatives on the Piccadilly Line and London Underground staff after union members voted to strike on the line .

'I apologise to Piccadilly Line customers'

Commuters expressed their anger on social media, with some claiming they were late to work as a result.

Tony Matthews, General Manager for the Piccadilly line, said: "I apologise to Piccadilly line customers whose journeys have been disrupted.

“We are repairing some Piccadilly line trains and unfortunately this means that currently we do not have a full fleet available.

“We are working hard to fix the trains as quickly as possible so that customers aren't faced with further delays.

“These trains are coming to the end of their lives which is why our planned deep tube upgrades - including the Piccadilly line - are so vital."