The timetable for the £650 million programme to electrify train services between Glasgow and Edinburgh has been announced with passengers set to enjoy a reduced journey time by the end of 2016.

The project is expected to bring down journey times between the two cities to 42 minutes.

Transport Minister Keith Brown also confirmed that electrifying other lines, which had formed part of the initial Edinburgh Glasgow Improvement Project proposal but earlier ditched from the scheme, would be completed – but not until 2018.

That applies to routes between Stirling, Alloa and Dunblane, with critics saying the announcement amounted to a delay in the project.

Mr Brown said rail services on the Whifflet route between Glasgow, Rutherglen and Coatbridge are set to be electrified four years ahead of schedule with work completed before the 2014 Games begin.

Mr Brown said: "The Scottish Government is determined to deliver rail services that connect communities with cities and people with jobs, and EGIP is playing a central role in delivering that ambition. The 42-minute fastest journey time on our flagship route between Edinburgh and Glasgow via Falkirk High is to be implemented, following completion of the electrification programme."

Scottish Labour's Richard Baker, said: "It's laughable that Transport Scotland and Keith Brown are describing EGIP as 'on track' when they have already cut funding and are now announcing further delays to the schedule."

A spokeswoman for Transport Scotland later denied that there had been any delays to the Government's programme.