A CHARITY which advises the body that chooses World Heritage Sites has warned Scotland's reputation in the field is under threat if councillors give the go-ahead to a controversial quarry project.

Proposals to excavate the green buffer zone around the protected New Lanark site will lead to the destruction of countryside near the Falls of Clyde and make environmental recovery impos-sible, a leading figure in the International Council for Monuments and Sites (ICOMOS-UK) warns today.

In a letter to The Herald, James Simpson, vice-president of the charity's UK committee, also said the threat to future tourism must play a large role in the final decision on building materials firm Cemex's plan by South Lanarkshire Council.

Mr Simpson wrote: "The threat to future tourism must be a significant factor in the authority's decision on Cemex's application – which will require to be endorsed by the Scottish Government.

"Much more significant, however, will be the effect of this decision on Scotland's international reputation as a responsible guardian of its own international recognised and respected heritage."

The warning carries particular resonance given that Scotland is due to submit an application early next year for the Forth Rail Bridge to gain the protected status, potentially becoming the country's sixth World Heritage Site.

Concerns that the bitter dispute over quarry plans near New Lanark could harm Scotland's chances of winning future Unesco recognition – a guaranteed boost for local tourism – were also shared by a group that opposes the move.

Professor Mark Stephens, leader of Save Our Landscapes, said: "When Historic Scotland made the nomination for World Heritage Status in 2000 it identified New Lanark's landscape setting as being 'essential' to its 'outstanding universal value'. It identified quarrying as a 'threat', and accordingly assured Unesco it would be 'prevented'.

"The documentation was signed by the First Minister on behalf of the Scottish Government. If the quarry goes ahead, Unesco might legitimately ask: 'Why should we believe Historic Scotland's assurances when other sites are nominated in the future?'"

Earlier this week it was revealed by The Herald that environmental agencies in UK and America had taken action more than 40 times following accusations of malpractice at Cemex sites.

The interventions followed claims that Cemex facilities had contaminated water, released a pollutant linked to acid rain and health defects in children without adequate permits, and broken other laws.

Mr Simpson also takes a swipe at Historic Scotland, the Scottish Government agency tasked with safeguarding the county's historic environment. He said: "Astonishingly, Historic Scotland has chosen not to object to the destruction of the very particular topography, which was the basis of the picturesque 18th-century planting – now urgently in need of restoration.

"Lowering the ground level by around 100ft will make any true recovery of this part of the setting of New Lanark and the Falls of Clyde impossible."

A spokesman for Historic Scotland said: "Our decision not to object to the proposed extension of the existing Hyndford Quarry was based on a thorough and detailed evaluation of the proposal."

He added the decision about Cemex's application is now with the council. It is due to make a decision this summer and will consider any new information submitted.

It also emerged this week that Cemex has paid millions of pounds in penalties for breaking environmental laws.