Any talk of the UK introducing conscription to the Army if Nato goes to war with Russia is “nonsense”, the armed forces minister has said.

Frontbencher James Heappey said the UK “long had plans” readied for “mobilising volunteers” in the event that Britain does enter a new conflict but stressed that “nobody is thinking” about bringing back conscription.

The remarks come after comments made by General Sir Patrick Sanders, the outgoing Chief of the General Staff (CGS), were interpreted as suggesting that conscription could be required in any potential future battle with Moscow due to the British Army being too small.

Sir Patrick, in a speech at the International Armoured Vehicles conference in south-west London on Wednesday, said Britain should “train and equip” a “citizen army” to ready the country for a potential land war.

Pointing to Sweden introducing a form of military service for its population, the head of the Army said at least 45,000 reservists and citizens should be trained up in the next three years to top-up the current army size of 74,000, in what he called a “whole-of-nation undertaking”.

No 10 ruled out any suggestion that conscription was under consideration, saying there were “no plans” to change the British military’s “proud tradition of being a voluntary force”.

Mr Heappey backed up that sentiment on Thursday, tweeting: “There are three issues being conflated into one in response to the CGS’s speech yesterday.

“Firstly, conscription. Nobody has ever mentioned it, nobody is even thinking about it. CGS didn’t say it. It is all nonsense.”

Models of conscription existed for two periods in the UK — during and after the first and second world wars — but compulsory military service has not been in force since 1960.

Ukraine brutally illustrates that regular armies start wars; citizen armies win them

But with a land war in eastern Europe raging for almost two years in the aftermath of Russia’s invasion of Ukraine, Western attention has turned to the readiness of Nato forces to defend its borders against any extension of Kremlin aggression.

Mr Heappey said there “will always be a debate about” whether the armed forces should be “bigger” after Sir Patrick pointed to Russian president Vladimir Putin spending “40% of public expenditure on defence”.

Defence Secretary Grant Shapps, who has previously backed defence spending rising to 3% of gross domestic product — a measure of the size of the economy — last week said it was currently below the target of 2.5%.

In comments posted on X, Mr Heappey said the UK Government was currently, at £50 billion per year, investing “more than we’ve ever spent before”.

He argued that UK forces, as part of Nato’s defensive alliance, were “overwhelmingly superior to Russia’s”.

But the Conservative defence minister said Sir Patrick had raised a “separate but equally necessary debate” about how the first wave of defenders can be bolstered in the event of a war.

“We have long had plans for remobilising service leavers and mobilising volunteers,” he continued.

“Similarly, (there are) requirements for industrial mobilisation.

“So this isn’t new and was in both the Reserve Forces 2030 review and the Defence Command Paper refresh.

“Strategic resilience plays a key part in deterring our adversaries.

“They need to know that we have not only got first echelon forces they don’t want to fight, but that as a nation we have got staying power to stay in the fight.”

He said such considerations would form an “important part” of the next integrated review of security and defence capabilities, following last year’s refresh of the 2021 review.

Sir Patrick’s comments came after Mr Shapps said the world is “moving from a post-war to pre-war world” and urged for the UK to ensure its “entire defence ecosystem is ready” to defend its homeland.

The CGS has been a vocal critic of cuts to troop numbers and military spending during his tenure.

He will be replaced as head of the Army in June by General Sir Roly Walker, an announcement that followed reports Sir Patrick was being forced out after having been outspoken.

Chief of the Defence Staff, Admiral Sir Tony Radakin, denied the claim when asked by MPs about the reports in July.