LONDON — With anti-Trident campaigners set to hold what will likely be  a major nuclear disarmament rally in London on Saturday, Britain's defense minister, Philip Dunne, has published a blog entry on the Conservative Home website laying out why the government is pushing ahead with a £32 billion (US $44.6 billion) program to build a new generation of nuclear missile submarines.

"The dangers we're facing are growing in complexity, diversity and scale. We can't predict the threats of next week, let alone what will happen in the 2030s, the 2040s and the 2050s. Disarming now would be a reckless gamble with our national security that would play into the hands of our enemies," said Dunne, who is responsible for Britain's £14 billion-a-year defense procurement and support spend. "Despite our honourable intentions [in reducing nuclear stockpiles to no more than 180 by the mid-2020s], a resurgent Russia repeatedly rattles its nuclear sabre while North Korea already this year exploded  a bomb and fired a ballistic missile in defiance of the international community."

The Campaign for Nuclear Disarmament protest comes ahead of the Conservative-controlled governments plan to hold a Parliamentary vote later this year on approving the next stage of the Successor program aimed at building four new Trident missile-equipped submarines to replace the current Vanguard class of boats starting in the early 2030s.

The march to stop the Trident proliferation is expected to attract thousands of protesters, but the attention of the event is likely to be shared with that created by the presence of Labour Party leader Jeremy Corbyn.

Corbyn's anti-Trident position has sparked a big row within the ranks of Labour parliamentarians and has split the Labour Party down the middle.

Labour's long-standing policy to support nuclear deterrence is under severe pressure, and recently appointed shadow Defence Secretary Emily Thornbury, herself anti-Trident, has refused to commit the party to the deterrent.

The Scottish National Party, which holds power in Scotland and now has a strong presence in the UK Parliament, is also vehemently anti-Trident and wants the Royal Navy's nuclear submarine base at Faslane, Scotland, to be shut down.

Labour has its own defense review underway at present, in part to decide what the official policy is on the nuclear deterrent for Britain's second largest party.

Whatever the outcome of the review, a substantial number of Labour parliamentarians are likely to vote with the government to approve the next stage of the Successor program.

Led by submarine-builder BAE Systems, the program is currently in its assessment phase. The company had been hoping for a contract to cut the first metal on the program this year, but with the 2015 Strategic Defence and Security Review pushing back the program by at least a couple of years, that may not happen.

One of Corbyn's recent unorthodox ideas was to build the new submarines but not equip them with missiles — a scheme meant to appease trade unions who fear the loss of thousands of jobs at companies like BAE and Babcock International should the Successor program not go ahead.

"Submarines without weapons? Let's get real. Our deterrence has to deter. Half-baked measures could be ruthlessly exploited by our adversaries," Dunne said.

The defense minister also used the blog on the Conservative Home website to dismiss claims by Thornberry that nuclear submarines' invisibility will be compromised by technology.

"Don't hold your breath. Admiral Lord Boyce, former First Sea Lord and submarine commander, says we're more likely to put a man on Mars within the next six months than make the seas transparent within the next 30 years. Such fears aren't stopping the US and Russia spending billions upgrading their submarine fleets," Dunne said.

Dunne's remarks follow a claim made earlier this year by Thornberry that technology advances in underwater drones will undermine the ability of the planned fleet of new submarines to operate undetected.

The shadow defence secretary told MP's recently that the Successor submarines could become as outmoded as World War II Spitfires.

The Parliamentary Defence Committee has subsequently taken up the idea and asked BAE and Babcock, the companies mainly responsible for building and supporting the Royal Navy's nuclear submarine fleets, to assess the feasibility and timing of the arrival of underwater drone technologies to detect submarines

Andrew Chuter is the United Kingdom correspondent for Defense News.

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