Britain is lifting the cap on the number of Trident nuclear warheads it can stockpile by more than 40%, Boris Johnson will announce on Tuesday, ending 30 years of gradual disarmament since the collapse of the Soviet Union.

The increased limit, from 180 to 260 warheads, is contained in a leaked copy of the integrated review of defence and foreign policy, seen by the Guardian. It paves the way for a controversial £10bn rearmament in response to perceived threats from Russia and China.

The review also warns of the “realistic possibility” that a terrorist group will “launch a successful CBRN [chemical, biological, radiological or nuclear] attack by 2030”, although there is little extra detail to back up this assessment.

It includes a personal commitment from Johnson, as a last-minute addition in the foreword, to restore foreign aid spending to 0.7% of national income “when the fiscal situation allows”, after fierce criticism of cuts in relief to Yemen and elsewhere.

The 100-page document says the increase in the nuclear warheads cap is “in recognition of the evolving security environment” and that there are “developing range of technological and doctrinal threats”.

Campaigners warned the UK was at risk of starting a “new nuclear arms race” at a time when the world is trying to emerge from the Covid pandemic. Kate Hudson, the general secretary of the Campaign for Nuclear Disarmament (CND), said: “With the government strapped for cash, we don’t need grandiose, money-wasting spending on weapons of mass destruction.”

The commitment is one of the most notable in the integrated review, a landmark post-Brexit review of defence and foreign policy, which also includes:

A clear statement that Russia under Vladimir Putin represents an “active threat” but nuanced language on China, which is described as posing a “systemic challenge” in a manner unlikely to please Conservative hawks on the party’s backbenches.

A commitment to launch an additional sanctions regime giving the UK “powers to prevent those involved in corruption from freely entering the UK or channelling money through our financial system” for the first time.

An aspiration for the UK to be a “soft power superpower” with praise for the BBC as “the most trusted broadcaster worldwide” despite Downing Street boycotting the broadcaster last year. The British monarchy is also cited as contributing.

The review began in the aftermath of the 2019 general election and is intended to help define the prime minister’s “global Britain” vision and shape future strategic direction, after leaving the EU, until 2030.

It contains only a handful of passing references to the bloc, arguing instead for an “Indo-Pacific tilt” in which the UK deepens defence, diplomatic and trade relations with India, Japan, South Korea and Australia in opposition to China.

“We will be the European partner with the broadest and most integrated presence in the Indo-Pacific,” the review says, while arguing that investing in cyberwarfare capabilities and deploying the new Queen Elizabeth aircraft carrier in the region later this year will help send a message to Beijing.

But it is the commitment to significantly increase the cap on nuclear warhead numbers that is the most significant development, coming after the UK promised to run down stockpiles following the end of the cold war.

Britain has far fewer warheads stockpiled than Russia, estimated to have 4,300, the US on 3,800 or China, which has about 320. But each warhead the UK holds is estimated to have an explosive power of 100 kilotons. The atomic bomb dropped on Hiroshima at the end of the second world war was about 15 kilotons.

“A minimum, credible, independent nuclear deterrent, assigned to the defence of Nato, remains essential in order to guarantee our security and that of our allies,” the UK review says in a section explaining the context for the stockpile increase.

Stewart McDonald, the defence spokesman for the Scottish National party, which is opposed to Trident renewal, accused the government of being wedded to an outdated defence policy: “For the prime minister to stand up and champion the international rules-based system before announcing in the same breath that the UK plans to violate its commitments to the international treaty on non-proliferation beggars belief.”

China lobby groups said they believed the review did not go far enough. A spokesperson for the Inter-Parliamentary Alliance on China said Beijing should not have been omitted from the list of countries engaged in hostile state activities.

“This is despite repeated Chinese state-backed cyber-attacks on UK targets and attempts by Chinese government agents to intimidate and threaten UK residents on British soil – and in stark contrast to Russia, Iran and other authoritarian states that have also targeted the UK,” the spokesperson added.

Further details of the plans for the armed forces will be contained in an official defence command paper to be published on Monday. That is expected to confirm a cut in the size in the British army to 72,500 – not mentioned in the review document – and investments in pilotless killer drones.

One idea not previously mentioned is a tentative proposal to create a citizen’s volunteer force – a “civilian reservist cadre” – potentially to work alongside the military in response to the future crises on the scale of the pandemic.