The UK is facing an alarming shortage of archaeologists integral to the success of major infrastructure projects such as the £55.7bn HS2 scheme, according to a new report.

House building, road upgrades and work on the rail networks planned over the next 17 years could be in jeopardy unless action is taken over the lack of trained workers, experts have warned.

Employers and universities are urgently working together to try to encourage school leavers into apprentice programmes and archaeological field schools to plug the gap.

There are 3,000 people employed in commercial archaeology in England, a number that will need to grow by at least 25% over the next six years, according to the report by public body Historic England (HE) to be published on Monday.

Projects touted as under threat by the lack of skilled workers include work on the Hinkley Point power station and the Thames Tideway Tunnel - a 15-mile "super-sewer" which will greatly reduce the amount of untreated sewage that overflows into the Thames.

Developers are required to fund archaeological excavation as part of planning permission policy introduced 25 years ago, a move that has led to "remarkable discoveries," according to HE.

Notable finds during excavation work on major infrastructure projects include the unearthing of the remains of an elephant, whose species is now extinct.

The animal, uncovered in Ebbsfleet, Kent during the works for HS1, was butchered with flint knives 420,000 years ago by pre-Neanderthals.

The only chariot racing stadium ever found in England was discovered during a housing development in Colchester.

In 2013 an "exceptional" Roman sculpture of an eagle clasping a serpent in its beak was unearthed by archaeologists in the final hours of a dig at a London building site.

Historic England's chief executive, Duncan Wilson, said his organisation was making "co-ordinated action" to ensure more trained professionals were in place to meet the upturn in demand.

He added: "Put simply, more spadework is needed, and this calls for us to think hard about how we can offer a new generation routes into the profession."

Nick Shepherd, chief executive of the Federation of Archaeological Managers and Employers, said: "The delivery of new UK housing and infrastructure depends not only on engineers and bricklayers, but also on archaeologists.

"Archaeological investigation is now a core part of the development process.

"This report makes clear that the government infrastructure plans over the next decade present a challenge to ensure sufficient archaeological capacity is in place to support construction of the new roads, rail and energy projects vital to economic growth."