IT is one of the most famous terms of opprobrium in Scottish history - the "parcel of rogues" who were alleged to have "sold out" Scotland in the Union with England in 1707.

The politicians who were "bought and sold for English gold" in the famous lines of the poem by Robert Burns have long lived in infamy in Scottish nationalist circles.

However, new research by a leading academic has found that the verses, which has always been thought to denounce the Union, were in fact written by an anonymous writer to attack the politicians involved in the disastrous Darien colonisation scheme of the late 1690s.

Professor Chris Whatley, historian and vice-principal of Dundee University, believes that the phrases were in circulation in the popular culture of early 18th century Scotland in song and poem form, and Burns, a collector of songs, only later wrote them down and they became "Such a Parcel of Rogues in a Nation".

Mr Whatley, whose latest book, The Scots and the Union, challenges the traditional view that the Scottish Parliament of 1707 was "bribed" into the union with England, said the verses had a more curious and complex history than once supposed.

"The fact is these phrases were sayings that pre-dated the Union, nationalist and Jacobite sayings that became used in a party-political fashion at a later date," he said.

"Also, although these phrases are now almost accepted as the political line on the Union, they were challenged and argued about at the time. The verses were created after the failure of Darien in 1699 or 1700 - a failure for many reasons, but one which some in Scotland blamed on the English - and they were aimed at those Scottish parliamentarians who supported the King (William) and his policies."

Mr Whatley said what was interesting was that those phrases - "a parcel of rogues/bought and sold with English gold" - were picked up and used by Jacobites and nationalists at a later stage.

"Well after the Union, and the failure of the Jacobite revolts in 1715 and 1745, the song remained popular and became sentimentalised."

Darien was an attempt by Scotland to establish a colony on the isthmus of Panama, but was a human and financial disaster, with crops failing and a high death toll by the colonists: its failure has traditionally been linked to the attraction of the Union to politicians by 1707.

The English government was opposed to the Darien scheme, English investors withdrew from it, and English forces in north America were told not to supply the embryonic colony.

It has been estimated that the scheme cost £400,000.

Mr Whatley added: "The song itself was not that well known until it was picked up again by the rising nationalist party in Scotland in the 1960s and 1970s, who used it often and now it is part of the culture."

He will be discussing the role of Burns in the Union at tomorrow's Burns International Conference at the Mitchell Library in Glasgow.