Britain should scrap plans to replace its Trident nuclear missile system and reallocate the cash to the Ministry of Defence's slashed budget, according to a thinktank report.

In its report Dropping the Bomb: A Post Trident Future, the liberal thinktank CentreForum argues that Trident's £25bn replacement cost cannot be justified in the context of £74bn of cuts in the MoD and no short or mid-term security threat.

"By scrapping Trident, the UK would be able to use the savings to increase the capacity of its conventional forces," the report said.

"Investing in conventional forces will be far more effective in protecting the UK's international status than replacing Trident."

Under the UK's current nuclear system, four submarines are armed with Trident ballistic missiles with nuclear warheads.

While the report cautions against replacing Trident, it also recommends that the UK should retain its ability to "design and produce nuclear-powered attack submarines to support the UK's global responsibilities".

The UK would only require its own active nuclear deterrent if a "decoupling" takes place between the UK and the United States to the point where the US would not defend Britain against a nuclear attack, according to the report.

The likelihood of such an event is as implausible as the threat of a new Cold War with Russia or China, the report said, undermining the need for an independent UK nuclear deterrent.