IT was a heartening moment on Monday to welcome the Prime Minister and his deputy to Wiltshire to announce the government’s decision to build a 1.8-mile tunnel under Stonehenge, which will be a new gateway to a fully dualled A303.

I am also delighted for the people of Winterbourne Stoke – whose lives will be transformed by a long overdue bypass.

The £1.3bn pledged to make this a reality represents not just the bulk of the £2bn pledged for the whole A303, but also the single largest investment in a heritage project in this country, which is testament to Stonehenge’s truly iconic status worldwide.

With such a tremendous list of investments across the country, it is particularly gratifying to know that Stonehenge was not simply one of many, but the jewel in the crown of a £15bn road strategy.

When I called for a 2.9km tunnel in my Westminster Hall debate in March, I said it was the only deliverable option.

I believe the determination of English Heritage and the National Trust to find a solution, plus the tireless efforts of my predecessor Robert Key and Councillor Ian West and local campaigners to keep this issue at the top of the agenda, have been key to unlocking it this week.

I know that some remain sceptical, and I have been asked on numerous occasions why this time is any different.

The coalition’s Infrastructure Bill currently going through Parliament includes a vital change to transform the Highways Agency into a Government owned company – with a protected six-year funding settlement enshrined in law.

I will be working hard to ensure this is delivered, and that the largest investment in our road network for a generation cannot be undone by any future government.

Despite the decades of scrutiny on over 50 alternative routes, we must also ensure the detail of this proposal is carefully examined. There are still questions being asked about the archaeological, environmental and hydrological impacts.

Having the eyes of the world on us gives us the opportunity and responsibility to deliver a tunnel that doesn't just meet environmental and archaeological standards, but sets them for the future.