Labour will not place an order for new nuclear-powered submarines until 2028, Defence Secretary Wes Streeting has confirmed, raising concerns about delays to the United Kingdom's naval expansion plans. The decision on the exact number of vessels to be commissioned will be made before the end of the design phase in 2028, according to a letter from Streeting to Shadow Defence Secretary James Cartlidge.
This timeline postpones a commitment that Sir Keir Starmer indicated would be made when Labour's Defence Investment Plan (DIP) was published. The DIP was released on June 30, but the party has now pushed the decision back by several years. In June 2025, Starmer had announced that "up to 12" of the new submarines would be ordered to replace the Royal Navy's Astute-class attack submarines.
The next-generation submarines, designated SSN-AUKUS, are based on a British design with technological input from the United States through the AUKUS security pact. These vessels are intended to feature a new Rolls-Royce PWR3-derived reactor, enhanced stealth capabilities, advanced sensors, and a vertical launch missile system.
Streeting stated in his letter that while the DIP outlines the intention to acquire up to 12 SSN-A submarines, a decision on the precise hull numbers is not required at this juncture. He added that the program is currently midway through its design phase and the number of submarines will be confirmed before the phase concludes in 2028. He also indicated that a new submarine would be delivered every 18 months from the mid-2030s, asserting that this delay would not impact the vessels' entry into service.
Shadow Defence Secretary James Cartlidge criticized the postponement, calling it "a shambles." He stated, "I could say I want to buy up to 12 Ferraris but if I don't have the money, I won't get any. The actual number of submarines was meant to be confirmed in the long-delayed DIP, but this was months late and left us none the wiser." He added, "Finally, Wes Streeting has had to admit Labour won't be able to tell us the answer until 2028. This is a shambles."
The UK's current fleet of four Vanguard-class submarines, which have a different strategic role, are slated for replacement by four new Dreadnought-class submarines, with the first expected to enter service in the 2030s. A Ministry of Defence spokesperson confirmed that the commitment to building up to 12 next-generation attack submarines remains unchanged and that a decision on exact numbers does not need to be taken at this stage, with no impact on the delivery schedule.
These developments follow recent comments from Prime Minister Andy Burnham, who stated that defence spending should not be prioritized over benefits. He argued that national security "cannot come at the expense of social security" and that strong national security also depends on community resilience. These remarks appear to contrast with Streeting's earlier statement that "there is no social justice without national security."
Britain's defense spending as a percentage of GDP has declined in recent years, placing it 13th in the NATO spending league table. Under Labour's current plans, spending is projected to increase from 2.6% next year to 2.7% by the end of the decade. This contrasts with projections from Germany, which expects to spend 3.5% by 2030, and Poland, which is already at 4.7%.