Thousands of trains have been cancelled and many stations closed as the result of the RMT’s first of three national strikes, which started at midnight.

An emergency service is running on some main lines between 07.30 and 18.30, but last trains will often run much earlier than this and there are no trains in Cornwall, much of East Anglia or in most of Scotland and Wales. Most branch and secondary lines elsewhere are also closed, and in most cases there are no replacement buses. All train operators are urging people not to try to travel today.

Where trains are running, only about 20 per cent of normal services are being provided. The situation has been worsened in south east England by a simultaneous RMT walkout on London Underground. The Transport for London website crashed, but before it went down it had warned of ‘severe disruption London-wide'. and urged people not to travel today. It has now (09.15) been restored.

Talks in a bid to avert the stoppages were continuing up to yesterday afternoon, but there was no agreement on pay increases.

The RMT is also concerned about threatened job cuts, although these have yet to be confirmed.

The Cabinet is meeting this morning, when Boris Johnson is expected to call for a compromise settlement. Ministers have already warned that large pay rises would also fuel inflation.

The walkouts are affecting 13 train operating companies and also Network Rail staff. Although neither Transport for Wales nor ScotRail are directly involved in the stoppages, their services are being seriously disrupted by the lack of Network Rail signallers and other safety-critical staff.

ScotRail said the closure of most boxes and signalling centres means that limited services can only run from Edinburgh to Glasgow and Bathgate, with services also running from Glasgow to Larkhall and Lanark. Avanti West Coast is running a reduced service between London and Glasgow Central, and some LNER trains from London are calling at Berwick-upon-Tweed and Edinburgh.

In Wales domestic trains are only running on parts of the Valley Lines in Cardiff. All other Welsh lines are closed, apart from limited GWR services between London and Cardiff Central.

Further 24-hour stoppages are due on Thursday and Saturday, and services on the intervening days are also expected to be disrupted.

UPDATE: The National Rail website also crashed temporarily at about 07.45.