The government will pay just £50 in exchange for permanent ownership and control of the earth beneath people’s homes as plans to build the High Speed 2 rail link under parts of Camden steam ahead.

The nominal valuation – which has been branded “comical” and “shocking” – was revealed as HS2 officers began meeting with communities in Camden to discuss the impact of the £50billion transport project.

By law, freehold ownership of land is supposed to include the ground below the surface to an unlimited depth – increasingly important as basement-builds add significantly to property values.

But at a packed meeting at Primrose Hill Primary School last Thursday, representatives from HS2 Ltd – the state-owned company responsible for delivering the rail project – prompted gasps as they revealed that compensation for ownership of subsoil would be just £50.

Hundreds of residents have already found themselves facing Compulsory Purchase Orders (CPOs) as part of proposed changes to sewer systems and the construction of the HS2 tunnels. The Secretary of State for Transport will eventually acquire “full and permanent” transfer of ownership of the earth.

Author and former MEP Stanley Johnson, who has been vocal about the impact of HS2 on his own house in Primrose Hill, branded the compensation “absurd”.

“Those of us who don’t have the ‘fortune’ of having our houses knocked down by HS2, and thus being fully compensated, find ourselves being offered ridiculous, derisory amounts like £50,” he said.

“I’ve no idea how they reached such an absurd figure – it certainly doesn’t reflect the damage that could face residents by way of noise or vibrations. And that’s not to mention the whole issue of subsoil rights.”

HS2 Ltd revealed that despite receiving hundreds of complaints, it still believed the amount a “suitable rate for subsoil for which there is generally no market”.

Cllr Chris Naylor, representative for Camden Town with Primrose Hill, said a cheque for £50 was “hardly worth paying”.

He said: “It’s a ludicrous valuation and my guess is that it was the minimum amount required for the government and HS2 Ltd to tick its boxes.”

Estate agents have also criticised the figure, with some already finding houses harder to sell because of HS2.

Hamish Gilfeather, manager at John D Wood & Co in Primrose Hill, said: “Typically, a basement build in Gloucester Road – where some of these CPOs have been sent – would add around £350,000 to the value of a home. To be offered just £50 – well, it doesn’t quite cover it.”

While HS2 representatives claimed that affected residents would still be able to build “typical basement extensions”, they were unable to make assurances that house values would not be affected.

They said property owners “may wish to seek professional advice in this respect”.

In December, former Director of Public Prosecutions Keir Starmer QC claimed the current framework for compensating those affected by HS2 was in breach of the European Convention on Human Rights, noting that it was neither “independent nor impartial”.