LONDON — British Defense Secretary Grant Shapps and other top officials were on a Royal Navy nuclear submarine when the test-firing of a Trident II D5 nuclear missile failed last month.

The misfire saw the missile crash back into the sea close to the submarine HMS Vanguard, which was undertaking demonstration and shakedown operations off the coast of Florida following a seven-year deep maintenance program.

Shapps confirmed the failure in a Feb. 21 statement to Parliament after reports of the Jan. 30 incident appeared in The Sun newspaper here.

It’s the second Trident test-firing in a row that went wrong for the Royal Navy. The previous misfire took place in 2016 when a missile veered off course and was destroyed.

Shapps was accompanied onboard HMS Vanguard by Britain’s top sailor, Adm. Ben Key, numerous media outlets reported.

Defence Procurement Minister James Cartlidge, appearing before the parliamentary Defence Committee on a separate topic on Feb. 21, confirmed he too was onboard along with senior unnamed U.S. officials.

Cartlidge declined to comment on a question from a committee member suggesting the failure was unrelated to the missile itself.

The Sun newspaper, which broke the story, reported that a Trident II was propelled into the air by compressed gas in its launch tube, but that its first-stage boosters did not ignite.

“On this occasion, an anomaly did occur, but it was event-specific, and there are no implications for the reliability of the wider Trident missile systems and stockpiles,” Shapps told lawmakers. “Nor are there any implications for our ability to fire our nuclear weapons, should the circumstances arise in which we need to do so.”

He added that the government “has absolute confidence that the U.K.’s deterrent remains effective, dependable and formidable.”

Britain’s two misfirings are in contrast to the performance of the U.S. Navy, which also operates the Trident D5.

The last test of an unarmed missile by the U.S. Navy took place in September when the Ohio-class submarine Louisiana fired the weapon off the coast of San Diego, California.

Like HMS Vanguard, the Louisiana was undergoing a demonstration and shakedown operation at the time of the firing.

Despite the British misfiring, Shapps said the submarine and crew were successfully certified and will rejoin the operational cycle as planned.

Vanguard is part of a four-strong fleet of nuclear missile-armed submarines operating with at least one submarine at sea and operational at all times.

A fleet of four Dreadnought-class boats, now under construction by BAE Systems at its Barrow-in-Furniss yard, are scheduled to replace the aging submarine fleet starting early in the next decade.

Andrew Chuter is the United Kingdom correspondent for Defense News.

More In Europe