Councillors unanimously backed the enlargement of the Clydebuilt development in Port Glasgow despite a last-ditch campaign by the shopping centre to have the proposal blocked.

Mall bosses say the expansion will take its shoppers away and have a ‘disastrous’ effect on Greenock town centre as a whole.

They expect to lose a fifth of existing tenants and predict retail provision in the town will shrink by a third.

The Mall’s £17m plan to rejuvenate the centre could now be scrapped and management have hinted that they could even look at the ‘disposal’ of the centre.

Today, a spokesman on behalf of the Mall owners said: “The team is considering all of its options and will be reviewing the situation.” At Wednesday’s planning board meeting, councillors were told developers already had approval to extend the Port site. This was granted three years ago along with the blueprint which saw B&Q, Costa Coffee and the Marston’s pub and restaurant built on the former shipyard land.

Their latest application sought to revise and ‘enhance’ the plans.

But shopping centre bosses today criticised planning board members for giving the go-ahead — and insisted that the goalposts had been moved.

A spokesman said: “This approval will now allow all types of retail development at this site. This is a relaxation of the previous planning permission given to the site in 2012 and a removal to an extent of the protection that was previously in place for the town centres.

“It also means that anything from a superstore to a coffee shop will be allowed, and we believe this will be in direct competition to existing retail units within Greenock town centre. We will now carefully consider our position.” Mall manager Claire Jefcoate also expressed her disappointment at the decision.

Ms Jefcoate, inset, told the Tele: “We’re disappointed, however we are still very focused on improving the Oak Mall and Greenock town centre.

“The campaign will continue because we need to continue raising awareness of the importance of the Oak Mall and Greenock town centre.” The approved plans include 11 new retail units, a family restaurant, a gym and a garden centre.

Alastair Dickie from Ediston Real Estate, who manage the project on behalf of owners Strathclyde Pension Fund, says construction will start in a matter of months.

He said: “We are delighted. It shouldn’t have been an issue. We’re just glad it went through. We think it will be a great investment to Inverclyde and look forward to starting on site in the summer.”