THE future of the Tesco development in Gerrards Cross hangs in the balance as the investigation into the rail tunnel collapse continues.

Jackson Civil Engineering, the company in charge of building work at the site, are hoping to submit their analysis of safety, feasibility and what they think caused the collapse next week.

From there, Network Rail and the Health and Safety Executive (HSE) will decide the future of the tunnel, based on the investigation, and when services can resume.

Richard Neall, chief executive for Jackson said: "They (the engineers) are going into all sorts of depths.

"You can't leave any stone unturned and it is taking a little bit longer than anticipated."

The operation to remove around 10,000 tonnes of spoil from the track was completed on Friday just a week after the collapse which devastated the railway network causing delays and confusion for commuters.

A Network Rail spokesman said: "The ultimate decision rests with us and the HSE, and we have to be satisfied ourselves with the results of that."

The collapse, which happened two weeks ago, will be brought to the attention of the Transport Minister in Parliament on Monday.

Beaconsfield MP Dominic Grieve has tabled an adjournment debate where he will raise concerns of Gerrards Cross villagers about the future of the strongly opposed superstore.

He will also speak on behalf of commuters affected by the extensive rail disruptions.

Transport Minister Karen Buck MP, will be taking questions from Mr Grieve about the repercussions of the collapse.

Mr Grieve said: "I am delighted to have secured the debate which will enable us to have the opportunity of raising with the Government, issues surrounding the causes of the collapse of the tunnel."

He added: "And to enquire what is being done to restore railway services and ensure that a safe service can be provided in future as well as considering the future of this unhappy development."