The UK’s leading maritime rescue charity has vowed to keep saving anyone in peril at sea despite provisions in draft legislation that barristers say could threaten volunteers with life imprisonment for picking up asylum seekers.

The Royal National Lifeboat Institution made the statement after immigration barristers warned that Clause 38 of the nationality and borders bill, published on Tuesday, potentially criminalised rescues of asylum seekers if they were deemed to constitute “facilitating” their arrival in the UK.

“We are a life-saving charity and, under maritime law and the Safety of Life at Sea Convention (Solas), our volunteer lifeboat crews will always go to the aid of those in danger at sea,” it said.

The statement marks the second time in a week that the volunteer-operated RNLI, which comes under the purview of HM Coastguard, has become ensnared in controversy over operations in the English Channel.

The organisation said on July 5 it was “incredibly proud” of its rescue work, despite criticism by the Daily Mail and Nigel Farage, the former Ukip leader, who said it was running a “taxi service for illegal immigration”.

Clause 38 amends an offence under the 1971 Immigration Act of assisting an asylum seeker. The clause increases the maximum sentence to life imprisonment, from 14 years, and removes the words “for gain”, which previously limited prosecutions to paid people smugglers.

Humanitarian organisations tasked with helping asylum seekers, such as Care 4 Calais, would still enjoy the protection of a specific exemption in the 1971 Act.

One immigration barrister, Colin Yeo, wrote on Twitter that it looked to him that the amended offence criminalised the RNLI or “anyone else conducting sea rescue” who was not specifically dedicated to helping asylum seekers.

George Peretz QC said that RNLI-type rescue operations involving asylum seekers seemed to fit the bill’s definition of “facilitating” the arrival of an asylum seeker in the UK. “It looks like a group like the RNLI would be committing that offence,” he said.

The Home Office insisted the bill targeted “ruthless criminal gangs” and that organisations and individuals would be able to continue to rescue those in distress in the sea.

However, Peretz dismissed that explanation because it provided no explanation of how the department would avoid criminalising rescuers.

“Mere assertion doesn’t cut it,” he said. All seafarers have an obligation under the UN’s Safety of Life at Sea convention to help people in distress that they encounter.

“I don’t think it’s just the RNLI,” Peretz added. “I think the shipping industry as a whole would have an interest in this.”

The International Maritime Organization, the UN’s body for maritime law, has also expressed concern, saying that any situation that increased the risk of loss of life at sea should be avoided.

The rescue issue is one of many to have emerged since the draft legislation’s publication.

The UN High Commissioner for Refugees on Wednesday warned that the bill risked breaching the UK’s obligations as a signatory of the UN Refugee Convention.

The British Dental Association attacked provisions for immigration officers to use dental X-rays to try to work out a migrant’s age — a method the organisation said was “inaccurate, inappropriate and unethical”.

The Home Office responded to questions about the issues by saying it would not rule out any option that could reduce “illegal immigration” and relieve pressure on what it called the “broken asylum system”.