£7bn HS2 contracts go out to tender even though scheme not yet backed by MPs

At least eight consortiums of Europe's largest construction firms will compete for the work for the high-speed line between London and Birmingham, which includes a 12-mile swathe near Lichfield.

HS2 is not set to be approved by MPs until the end of 2016 at the earliest but HS2 Ltd, the taxpayer-funded company responsible for the new railway line, has spent £1bn and taken on 1,000 staff.

The contracts will be worth between £700m and £1.1bn each with tendering starting in September.

Companies reported to be interested in the contracts are Acciona of Spain, Hochtief of Germany, and Dutch company Volker which has formed a joint venture with France's Bouygues and UK construction company Sir Robert McAlpine.

Stop HS2 campaign manager Joe Rukin said: "We've always said that HS2 Ltd would blow as much cash as possible to try and make the project impossible to cancel. They've spent the best part of £1bn and now we learn they will start bids on contracts worth another £7bn next month, all before the HS2 plans get passed by Parliament. None of this needs Parliamentary approval, because MPs and Lords signed a blank cheque for HS2 two years ago.

"What is happening here is clear. It doesn't matter how bad the case for HS2 is, how terribly the project is being managed, or where the real cost now is. This Government wants HS2, and as such they will blow as much money as possible to make it seem like a waste not to go ahead. This is typical of dogmatic politicians, but really, now the money being talked about is silly. If the £7bn of tenders is really just for tunnels and viaducts on Phase 1, it just shows the project is over-budget, yet again."

HS2 has a budget of £50bn and will pass through a total of 45 miles of rural Staffordshire over its two planned phases.

Campaigners say it will do irreversible damage to the countryside, blight communities, and that the business case does not stand up.

Professor Tony Travers from the London School of Economic said: "Once the digging starts, it makes it even harder to stop. The more big contracts are let and the more people they bring in from other organisations, the harder it is to back out. It would be financially expensive and hugely politically embarrassing to row back from that."

HS2 spokesperson Ben Ruse said: "Our Parliament recognises the value of advance planning for the long term success of major infrastructure projects like Crossrail and 2012 Olympic Games. This is why in 2013 Parliament voted to allow HS2 to begin detailed planning and industry engagement prior to Royal Assent.

"This extra time will benefit business, by giving them a head start to make the investments they require in recruitment, training and education to help them win work on HS2 – and help us ensure the project remains on time and on budget."