Francis Wenban-Smith, palaeolithic specialist for Oxford Archaeology, described the findings as “exciting”.

“Artefactual evidence of this period is exceptionally rare in the Upper Thames landscape north of the Goring Gap,” he said.

“The presence of flint tools gives an insight into the mobility of these ancient humans, since flint raw material would not have been available at the site.”

Carl Champness, the project’s manager, said it was “only the start of the story”.

“We hope planned further investigation and detailed analysis of these remains, will help enhance our understanding of the early occupation of Britain,” he added.

No major archaeological remains were identified, according to Oxfordshire County Council, meaning the £17m project will now go ahead.

Main construction is due to start in spring 2025 and will see the road widened to improve capacity, with new south-facing slip roads built.