Conservative ministers have denied a multi-million pound upgrade to the submarine testing range off Skye is "stealth" preparation for Trident renewal.

SNP MP Brendan O'Hara said it was "difficult to comprehend" that the proposals had nothing to do with replacing the ageing weapons system on the Clyde.

Defence minister Philip Dunne said that the plans had no "specific relationship" with the nuclear deterrent.

Mr O'Hara questioned the minister during a Commons debate on moves to expand the British Underwater Test and Evaluation Centre (Butec), where submarine weapons are tested.

MPs have yet to agree to renew Trident, at a cost of billions of pounds, although the Conservatives have said that they are committed to a like-for-like replacement.

MPs are expected to vote on the issue sometime next year.

Ian Blackford, the SNP MP for Ross, Skye and Lochaber, also warned the minister that large-scale expansion of Butec would lead to a "collapse" in fish stocks and the local fishing industry, potentially causing "depopulation".

Mr Dunne told him that the area concerned was "relatively modest" and "certainly not the much larger area the honourable gentleman seems to think".

He added that he did not share the "apocalyptic vision" of the future for the fishing industry.