The nine, who were first shortlisted in March this year, have all been invited to tender for the civil engineering package for phase one of HS2, covering London to Birmingham, worth up to £8.6bn (see box, below).

Later in the tendering process, successful firms will also be eligible to bid for a further £1.8bn-£3.3bn of work for phase 2a, which covers works from Birmingham up to Crewe.

The firms have been invited to tender for the following works packages:

• Lot S1 – Euston tunnels and approaches (£600m-£900m)

• Lot S2 – Northolt tunnels (£850m-£1.4bn)

• Lot C1 – Chiltern tunnels and Colne Valley viaduct (£800m-£1.3bn)

• Lot C2 – North Portal Chiltern tunnels to Brackley (£800m-£1.3bn)

• Lot C3 – Brackley to Long Itchington Wood Green tunnel south portal (£600m-£900m)

• Lot N1 – Long Itchington Wood Green tunnel to Delta Junction / Birmingham Spur (£900m-£1.5bn)

• Lot N2 – Delta Junction to West Coast Main Line tie-in (£800m-£1.3bn)

Civil engineering contracts covering the 225 km phase one are expected to be signed in 2017, with work starting on site a year later.

In total, the first phase of the project is forecast to create 14,600 construction jobs and apprenticeships.