However, the official added they thought Starmer would still try to get the plan through before the NATO summit, since it would be difficult for him to reassure allies on the U.K.’s spending commitments without it.
Others questioned whether an outgoing prime minister would be able to secure agreement on such a politically sensitive plan.
Simon Case, a former Cabinet secretary, told The Times: “Why would the MoD want to agree something with an outgoing prime minister? Anything that an outgoing prime minister announces is unlikely to be taken seriously by anybody.”
Defense industry representatives will be invited to Downing Street on Wednesday to meet officials from No. 10 and the Ministry of Defence as the government tries to persuade the sector it is still determined to provide certainty for manufacturers via the long-awaited plan.
Defense firms are torn on the issue of timing, said one lobbyist, as they are “desperate” for certainty but attracted by the idea that a new administration might find a way of increasing spending.
A spokesperson for Burnham declined to comment. A spokesperson for Starmer pointed to remarks from Deputy Prime Minister David Lammy, who told MPs on Monday: “I can confirm that the Defence Investment Plan will be published before the NATO summit.”