The Government was today signalling a major shake-up of the running of the railways.

Transport Secretary Alistair Darling was announcing to the House of Commons that the Department for Transport was starting a review of the rail structure.

To be completed by around July, the review could weaken the power of the Strategic Rail Authority (SRA) which is led by the crusading former Virgin Trains executive Richard Bowker.

There were rumours over the weekend that Mr Bowker - whose no-nonsense style has not met with universal approval - was resigning or was about to be sacked.

These rumours were denied by the man himself and by the Department for Transport.

It is also thought the review could recommend the setting up of eight regional controllers with responsibility for both tracks and trains - restoring the link broken by privatisation.

There has long been unhappiness in some quarters about the role of the Health and Safety Executive (HSE) in overseeing rail safety through its Railway Inspectorate.

It is possible the department's review may also take this responsibility from the HSE and possibly move it to the newly-constituted Office of the Rail Regulator when the present regulator Tom Winsor stands down later this year.

Over the weekend, Commission for Integrated Transport chairman David Begg said that any move to downgrade the role of the SRA would be a ''retrograde step''.

However, Mr Darling and the Government are acutely aware of the importance of the need to improve - or at least to be seen trying to improve - the performance of the railways in the run-up to a General Election that could come as early as May 2005.

The department's review is expected to come out in time for the Chancellor's spending review which will now coincide with the SRA's annual strategy report which had been due out this month but has now been put back.

''Quite a lot of people's roles could change from now on,'' a rail industry source told PA today.

He went on: ''There are lots of different organisations with overlapping responsibilities. The plan is to reduce the amount of overlapping and bring the train companies and track operators more closely together.

''The review report will come in the form of a consultation document and there may need to be new legislation afterwards.''