Anti-HS2 protesters say they will stay in underground tunnels for as long as it takes even after a judge rejected a legal bid to halt efforts to evict them.

Environmental campaigners have spent six nights underground after digging a network of tunnels beneath Euston Square Gardens, next to Euston station in central London, and are prepared to sit it out for weeks despite an ongoing eviction process.

They want to protect the green space which they claim will be built over with a temporary taxi rank before being sold to developers as part of plans for the high-speed railway.

HS2 Ltd said it has “legal possession” of the land and urged protesters to leave “for their own safety” before they are removed by High Court enforcement officers.

A spokesman for HS2 Ltd said High Court enforcement officers can lawfully remove trespassers from land acquired by HS2 Ltd and are able to use minimum force to do this under powers granted by the High Speed Rail (London – West Midlands) Act 2017.

In an order issued on Monday evening, High Court judge Mr Justice Robin Knowles refused an application brought by Dr Larch Maxey, one of the activists in the tunnels, for an injunction requiring HS2 and others to cease operations.

The order says Dr Maxey should cooperate with HS2 Ltd, the Health and Safety Executive, the London Fire Brigade and the police “to leave the tunnel safely and allow others to do the same”.

It adds that Dr Maxey should “until further order… cease any further tunnelling activity and is not to cause any other person to engage in tunnelling”.

The judge’s order notes the situation Dr Maxey is in “is very dangerous”.

Protester Blue Sandford, 18, from London, is a member of HS2 Rebellion, an alliance of groups and individuals campaigning against HS2, and spoke to the PA news agency by phone from the tunnels on Tuesday afternoon.

“I’m prepared to stay here for weeks,” she said, and asked if she was afraid considering the judge described the situation as “dangerous”, she replied: “I’m afraid of the climate and ecological emergency.”

Ms Sandford said: “I feel completely safe in our tunnels.”

She said it is unlikely bailiffs will remove all nine protesters on Tuesday, adding: “I think they’re trying to get into the down shaft at the moment, which we’ve barricaded, and we’ve got a lock on that they might be able to reach today.

“But I don’t know if they’ll get anyone out today.”

Asked how long she is prepared to stay there, Ms Sandford said: “As long as it takes. I have no plans to get hurt or die down here.

“That’s completely not what I’m about. So if I run out of water then I will come up, but I’m prepared to be here for the long haul.”

She said efforts to stop climate and ecological emergency is “such a big fight”.

The protesters’ legal team were expected to arrive at the site on Tuesday afternoon in the hope of taking instructions from their clients at the entrance to the tunnel.

A HS2 Ltd spokesman said: “The safety of people trespassing and the safety of HS2 staff and agents in this operation is of paramount importance.

“We are doing all we can to end this illegal action quickly and safely, including providing those underground with air – despite claims to the contrary.

“It is forecast to rain regularly over the next 48 hours and we have repeatedly raised concerns to the activists that their crude tunnels are simply not equipped to deal with these weather conditions.”

Meanwhile, a spokesman for HS2 Rebellion said up to 25 anti-HS2 campaigners have entered the main HS2 site near Euston station and occupied buildings, diggers, a crane and other machinery.