Britain’s defence minister has said that Islamic State remains “the most significant terrorist threat to the United Kingdom and our interests”.

During a Counter-Daesh Update in the House of Commons this week, Secretary of State for Defence Ben Wallace said that since July 2019, RAF aircraft had struck 40 terror targets in Iraq and Syria.

While Islamic State has lost much of its territory in the Middle East, the minister said that nevertheless the prospect of resurgence “should concern us all” and committed to retaining a presence in the region to support the global coalition.

He added that “as long as it is able to operate over there, it can hit our citizens over here. Daesh [Islamic State] retains its intent to carry out and inspire attacks against us and remains the most significant terrorist threat to the United Kingdom and our interests.”

In recent years, British intelligence services and counterterrorism specialists have said that Islamic State had been plotting attacks on the UK and Europe, perpetrated by British-born jihadists returning to the UK.

The defence minister said on Wednesday that of the 30,000 foreign fighters to take up arms for Islamic State in Syria and Iraq, 900 came from the United Kingdom.

“Of these, approximately 20 per cent have been killed; 40 per cent have returned to the United Kingdom, where they have been investigated, and the majority have been assessed now to pose no risk or a low-security risk; and some 40 per cent remain in the region, either at large or in facilities managed by the Syrian Democratic Forces or others,” Mr Wallace said.

The assertion that the majority of returnees have been assessed as posing “no” or “low” risk counters other claims in recent years. A report from Europol in June 2019 found that the UK had a high rate of “exceptionally dangerous” returning ISIS fighters. A May 2017 report by The Times claimed that 350 returnees posed a threat to British national security.

Recent figures reveal that the UK’s domestic intelligence agency MI5 has 43,000 people in Britain on the terror watch list — nearly double the number disclosed in 2017 — of which, 3,000 are Subjects of Interests being closely monitored.

The ISIS update comes against the backdrop of former teen ISIS bride Shamima Begum winning her Court of Appeal battle to return to the United Kingdom to challenge the government’s decision to strip her of her British citizenship. The hawkish neoconservative think tank The Henry Jackson Society estimates that some 150 dual-national jihadists stripped of their British citizenship could launch their own legal challenges to be able to come back to the UK to challenge their own ex-communications.

“The already overworked security services will have their work cut out with this potential sudden influx. This decision could have dramatic repercussions for our entire counter-terror strategy,” Dr Alan Mendoza of the HJS said last week.

While the government’s Independent Reviewer of Terrorism Legislation, Max Hill QC — now the Director of Public Prosecutions — had said in 2017 that many returning jihadists were not being prosecuted. He added in his belief that they should instead be reintegrated into British society, arguing that some may have been “brainwashed” or were very young when they went to the Middle East to join the terror group.

However, a former member of al Qaeda who became an MI6 spy said in February that there “is no such thing as a rehabilitated jihadist” and efforts by British authorities to do so “are riddled with naivety and a lack of understanding”.

Aimen Dean called jihadists “extremely treacherous” and suggested “much longer sentences and make them serve the minimum in its entirety unless they show remorse and co-operation. If you need another Belmarsh [prison], build one.”

His remarks came after the London Bridge and Streatham terror attacks committed by Islamists who had been released early from prison. Usman Khan, the London Bridge attacker, killed two people coordinating a de-radicalisation event that Khan was attending at the time. In December, Khan’s lawyer admitted that his client might have deceived him over his reformation.

A former minister told the House of Commons that 163 convicted terrorists in the past seven years had been released early onto the streets of Britain.