More than 350 jobs to be created at site

Hundreds more are expected to follow as part of the Phoenix 10 project. The land will first need major reclamation work because of contamination, while dozens of mineshafts are set to be filled in or dug out.

It comes amid concerns over spiralling costs to redevelop the old James Bridge IMI Copper Works site. Walsall Council has stepped in to lead the project after private sector developer Parkhill Estates pulled out at the end of last year.

Parkhill had initially estimated the transformation of the 37-acre plot would cost £18 million but the price is now expected to soar. Money will need to be borrowed by the council and then repaid through business rates. Coal recovered during the clean-up of the contaminated site will also be sold off to help fund the scheme.

Work is due to begin in early 2015. The Phoenix 10 site is one of the key parts of the enterprise zone, which includes 14 sites in Darlaston and five in Wolverhampton. This includes the i54 site near Wolverhampton where Jaguar Land Rover is building a £500m engine plant.

Overall 3,000 new jobs across the Black Country are anticipated. The authority says the exact number of jobs on the IMI site will be dependent on which firms become established on the site. Walsall Council head of regeneration Simon Tranter said: "There are very few sites of this size located adjacent to a motorway in the region, which will make a key contribution to employment.

"This is the biggest single site in the enterprise zone after the i54. The important thing is the ground is stable, any developer who wants to buy the site or lease the site needs to know it is safe.

"This is an important site, the benefits that it brings not only to Walsall but the region are huge." The main landowner is currently the Homes and Communities Agency, with the council due to take control.

But Labour group leader Councillor Tim Oliver said the project had been mismanaged from the start.

"We have to ask why the budget has spiralled and what is being done to ensure costs don't continue to climb," he said.