Military chiefs are reportedly looking at scrapping the UK's fleet of tanks and instead focus on other capabilities such as cyber warfare.
A report by The Times suggests the plans have been drawn up as part of proposals to radically modernise the Armed Forces and cut costs.
It claims the Government will examine the idea, as the cost of upgrading Britain's 227 Challenger 2 tanks, and the supporting 388 Warrior armoured fighting vehicles, has soared.
Last year, then-Defence Secretary Penny Mordaunt said both vehicles were "obsolete".
Lucy Fisher, Defence Editor for The Times and the journalist behind the report, told Forces News the place of the tank in the UK Armed Forces is now "incredibly vulnerable".
"UK military liaison officers have been dispatched to start floating this proposal with senior NATO members, the US Army in Europe and also in NATO land command in Izmir in Turkey," she said.
"Obviously, if we did pull back from heavy armour, that would have huge impact on our military contribution to NATO."
The report comes months before November's expected conclusion of the Integrated Review - described by Downing Street as the biggest review of British defence, security and foreign policy "since the end of the Cold War".
New defence landscapes such as cyber and space were detailed by the newspaper as a priority for the military.
A Government source was quoted in the report saying "a number of bold decisions" must be taken to "rebalance" Britain's defence interests.
WATCH: Tank expert David Willey shares his thoughts on the news.
Under the proposal, the newspaper claims the Challenger fleet would be placed in "deep preservation" and could still be called upon in a crisis.
The article states the UK is "sounding out" NATO partners for an overhaul in its contribution to the military alliance.
While the Challenger 2 could still be replaced or upgraded, Britain is reportedly set to instead focus on taking on a new leadership role in attack aviation - offering all 50 Apache helicopters to the allies, as well as heavy-lifting refuelling and battlefield reconaissance helicopters.
This is said to be in addition to "cyber, electronic and unconventional warfare capabilities".
"Whether that goes down well with NATO and they accept that as an acceptable switch from tanks remains to be seen," said Ms Fisher, adding the alliance has previously been "unelastic" with proposals deviating away from traditional lineups.
David Willey, curtor at The Tank Museum, told Forces News tanks remain a vital part of defence.
"If we want to have a credible defence, tanks are still part of that make up that means you're a serious army," he said.
"If anyone claims they've [tanks] have come to the end of their working life, look on the news, look around the world, tanks are being used all over the place still."
Tobias Ellwood MP, Chair of the Defence Select Committee, tweeted the move "looks like another cost-cutting exercise".
Other savings measures detailed in the report include the closure of an Army training base in Alberta, Canada, although an anonymous military official reportedly questioned the impact on Britain's status if the plans did go ahead.
A spokesman for the Ministry of Defence said: "Our commitment to NATO is unwavering, and the UK recognises that as a global military power our greatest strength remains our alliances.
"We are engaging our international allies and industry partners as we develop and shape defence’s contribution to the integrated review."
The spokesman added that "no decisions have been made regarding troop positioning".