South Western Railway (SWR)'s finances are "not sustainable in the long term", the government have said.

That's according to Transport Secretary Grant Shapps.

Shapps listed the train operator's poor punctuality and reliability, combined with slower revenue growth, as reasons for their recent weak financial performance.

In the year up to March 2019 SWR made a pre-tax loss of £139 million after suffering from infrastructure failures and industrial action.

The Transport Secretary said SWR's recent finances were "significantly below expectation" since the franchise began in August 2017.

The franchise is owned by FirstGroup and MTR.

The operators have "not yet failed to meet their financial commitments", Shapps said, while adding that the Department for Transport "must prepare suitable contingency measures".

Potential options include issuing a new short-term contract to SWR's owners - FirstGroup and MTR - or transferring the operation of trains to public-sector body the Operator of Last Resort.

Mr Shapps said SWR would "continue to operate as usual with no material impact on SWR services or staff" while a new approach is worked out.

He added: "Across the country, a number of franchises are failing to provide the reliable services that passengers require and there are legitimate questions on whether the current franchising model is viable.

"Keith Williams - who is leading an independent review into the railways - has already stated that franchising cannot continue in its current form.

"His review will propose sector-wide reforms which aim to put passengers at the heart of the railway."

Industry figures show that, between December 8 and January 4, the proportion of scheduled train stops made within one minute of the timetable by SWR was 55 per cent compared with the average across Britain of 62 per cent.

Members of the Rail, Maritime and Transport (RMT) union on SWR have staged a series of strikes stretching back more than two years in a dispute over guards on trains, which has caused travel misery for passengers.