Former Liberal Party leader Lord Steel has claimed the £300 million now being spent on the new Borders Railway line could have been avoided if politicians had worked together in the late 1960s when it was closed.

Recently disclosed Cabinet papers from 1969 indicated that Willie Ross, the then Scots Secret­ary, had argued for the retention of the line from Edinburgh Waverley to Hawick to assist with economic development in the Borders.

But he never enlisted the support of local MP David Steel and Conservative MP Lord Dalkeith and a specially commissioned expert's report supporting his case arrived too late.

Speaking at a 45th anniversary dinner in Newcastleton marking the closure of the Waverley line, Lord Steel Of Aikwood argued the present "necessary but extravagant" expenditure to re-open the line could have been avoided if Mr Ross had been more open with him.

He pointed out Cabinet papers from the time showed Mr Ross, later to become Baron Ross of Marnock, was arguing to save the top half of the line from Edinburgh to Hawick as closure ran contrary to rejuvenating the Borders economy.

Lord Steel, an MP in the Borders from 1965 until 1997, said: "You may recall that I had persuaded the local authorities in the three counties to commission and finance a report from railway expert Professor John Hibbs, who had argued precisely that case in his report, including the closure of smaller stations, single line track, and de-manning of larger stations. But the report came too late in the day and Willie Ross never let known his own views. To be frank, politicians in those days tended to be party-parochial.

"The then Tory MP for Edinburgh North, Lord Dalkeith, (later Duke Of Buccleuch) who lived in the Borders, was a stalwart supporter who, along with me and Madge Elliot, delivered a petition to 10 Downing Street. But neither of us had any dialogue with Willie Ross, who was an entrenched Labour man.

"If the three of us had been united we could probably have saved the line to Hawick. Also, we would have saved the current necessary but somewhat extravagant expenditure of nearly £300m to reinstate the line as far as Galashiels.

"We have to make a success of that, and fortunately all the branch lines that have reopened in Scotland have exceeded the predictions of travel on them.

"I have two minor quibbles about the proposed new line: first, the journey estimates are too slow - we do not want clapped out rolling stock from elsewhere - it must operate at higher speeds. Second, although the terminus is rightly placed at Tweedbank-Abbotsford, it would be sensible to extend the line a mile or so to the existing Melrose station, especially to cater for incoming excursion trains."

Lord Steel, 76, said it was the biggest disappointment of his career as an MP when the Waverley line was lost as part of the Beeching cuts.

He travelled on the last train on the line between Edinburgh Waverley and London Pancras Station on January 5, 1969, and said it was his ambition to travel on the first train on the newly built line in 2015.

Newcastleton is the only place in Britain where an inter-city train has been held up by a demonstration. Protesters lined the track in 1969 and blocked the final train on the Edinburgh-Carlisle Waverley line, leading to the arrest of the local minister.