PLANS for a high speed train between Glasgow and Edinburgh were doomed from the start because the project was never financially viable, it has been claimed.

Willie Rennie, leader of the Scottish Liberal Democrats, accused ministers of making "overblown" promises to cut journey times between the cities to less than 30 minutes.

He hit out after transport minister Derek Mackay refused to published a business case on the scheme prepared for ministers in 2014.

Mr Rennie said: "I suspect the refusal to publish the business plan reveals that the Edinburgh to Glasgow high speed line was never financially viable.

"The government now needs to publish the business plan so we can fully understand whether their overblown claims ever had an element of merit."

Nicola Sturgeon, the then-infrastructure minister announced plans for the high speed link in 2012.

She said 140mph trains would cut journey times to less than 30 minutes.

She said the scheme could be completed by 2024 and stressed it would not be dependent on, the UK Government extending the planned HS2 high speed line from London to the north of England  on to Scotland.

However, in a parliamentary answer last week, Mr Mackay revealed the project had been dropped as it  "depends on the high speed route coming up from the south".

He said the decision was based on a draft business plan in 2014.

Mr Rennie hit out after questioning the minister at Holyrood.

Mr Mackay denied the high speed link had been shelved but confirmed it was "not possible to progress planning".

He said the Scottish Government had been working with the Department for Transport to identify route options from extending HS2 to Scotland and their conclusions would be published shortly.

He told MSPs: "In terms of 2012, when that position was outlined, there wasn't a commitment from the UK Government - there wasn't even a suggestion from the UK Government - that high speed rail would come to Scotland.

"There is now an opportunity to integrate our ambitions and aspirations, which we have stated, in a way that works in partnership and is a sensible approach".

The government hopes the London to Birmingham section of the £55.7billion HS2 line will be completed by 2026, and further routes to Manchester and Leeds by 2033.

Speaking in 2012, Ms Sturgeon said the Scottish Government would "not wait" for Westminster to deliver a route to Scotland and would be "firing ahead" with its plans for a high speed link between Glasgow and Edinburgh.