Discussions are ongoing over the control of Scotland's railways

Richard Bowker is set to tell business leaders and politicians in Edinburgh that there should be a limit to the transfer of powers north of the border.

He wants measures to ensure the railways remain an integrated system.

There is considerable funding either planned or already under way in the Scottish rail system.

'Integrated network'

Work is continuing on upgrading the West Coast main line and further projects to expand the network are planned.

Currently Scottish ministers control and fund the ScotRail train franchise, but power over Network Rail, which owns the tracks, remains in London.

The Scottish Executive is currently in negotiations with the Department for Transport in London to bring the rail network north of the border under overall Scottish control.

However Mr Bowker believes that control of Scotland's railway network should not be divorced from the rest of the UK.

He wants any proposal for change to make sure the network is integrated and that Scotland is not left isolated from it.

Mr Boweker told BBC Radio Scotland: "Local and regional services deserve to have a very great deal of input from local, regional and - in this case - devolved nation bodies.