On the first weekend of the general election campaign, Rishi Sunak unveiled his first headline-grabbing policy promise: introducing mandatory national service for teenagers. The proposal – wherby 18-year-olds would either join the military for 12 months or volunteer at weekends – sparked incredulity and ridicule. But Tory strategists introduced it for a very specific reason – one that goes to the heart of their election strategy. For months, Sunak’s aides have said they can pull off the apparently impossible and overturn a 20-point poll deficit by running a campaign that forces voters to look seriously at their two main rivals: Labour and Reform UK. Its overarching focus will be security. By hammering home that message, the Tories hope to make voters – particularly Reform voters – nervous about the prospect of major change under a Labour government. “Everything in the campaign falls under the ‘security’ banner,” said one senior Conservative official. “That will mostly be about the economy, but also security of borders, safety on the streets at home and global risks that affect your economic security.” Sunak’s aides are hoping that a policy blitz designed to appeal to Reform UK voters, combined with the fact this summer election has caught Richard Tice’s party unprepared, will tempt voters back to the Conservatives in the coming weeks. A YouGov poll carried out after the election was called put Labour on 44%, the Conservatives second on 22% and Reform UK third on 14%. By shaving some points off Reform’s share, the Tories hope to start narrowing Labour’s lead in the first weeks of the campaign. Tory insiders say their message will be focused on the two main themes of the economy and immigration. Both strands contain risks, however. On the economy, the Tories are planning to focus heavily on Labour’s spending plans, which they say will involve tax rises that Keir Starmer is trying to hide from view. Speaking on Sunday morning, Rachel Reeves ruled out rises to income tax and national insurance under a Labour government The prime minister last week alleged a Labour government would cost every household an extra £2,000 a year, based on an analysis published by the Conservatives suggesting a £10bn gap in Labour’s spending plans by 2028-29. Tory officials admit privately, however, that their economic argument has been hampered by the damage done to the public finances by Liz Truss’s “mini-budget”, after which the party’s reputation for economic competence has struggled to recover. Some around Sunak want him to tackle this by being more willing to criticise Truss publicly. This has been made more difficult, however, by the fact the former prime minister appears to be planning to run again for her seat in South West Norfolk. One Conservative minister said: “The one thing which would really help our campaign is if Liz Truss announces she is standing down.” On immigration, meanwhile, the Conservatives are hoping to use their scheme to deport asylum seekers to Rwanda as a dividing line with Labour, which has promised to scrap it. They say Sunak’s admission on Thursday morning that there would be no flights to Rwanda before the election was designed to make that choice even more stark. “The campaign is about security, and immigration is about security,” said one of the prime minister’s aides. “The message is, flights [taking] off with us, flights grounded and an amnesty for illegal immigrants under Starmer. It’s that simple.” The risk here though is that in delaying the Rwanda plan, Sunak has played into the hands of the anti-immigration party Reform UK, which is threatening to peel millions of votes away from the Tories. Richard Tice, Reform’s leader, was keen on Thursday to talk about the prime minister’s admission. “We know the Tories have lied to us,” he said. Nigel Farage told Sky News on Sunday that any vote for the Conservatives or Labour party was a vote for “mass immigration”. Some Conservatives also worry that by trying to turn immigration into a campaign theme, the party will detract from the central economic message. Craig Oliver, former director of communications in Downing Street under David Cameron, said: “The reality is most elections are won and lost on who is the best leader and who is best to run the economy. If you can answer both those questions positively you’re almost certainly going to win.” He added: “Successive administrations have told people they have an answer to immigration and then failed to deliver it. We now know there will not be a plane that takes off for Rwanda before the election, and voters are going to think we have invested endless energy and a lot of money trying to enact and communicate a plan that is not going to happen.” Sunak is expected to sell the message mainly through highly orchestrated campaign stops at different points across the country. On Thursday, he held an event at a factory in Derbyshire where he was questioned by two men in hi-vis jackets who turned out to be Conservative councillors. He then went to an event in Wales where reporters were told not to take any photographs or video, not to report on the event in real time, and not to ask questions about national issues. The strict rules over Tory events have not prevented gaffes, including the moment the prime minister asked workers in a Welsh brewery whether they were looking forward to the Euro 2024 football tournament, for which Wales has not qualified. For some Tories, incidents such as these prove why it was a mistake to put the prime minister at the centre of a presidential-style campaign rather than relying more on other frontbenchers. They point to a memo written shortly before the election campaign by the Conservative minister Johnny Mercer, which warned the strategy “appears to be all about placating him/managing him/promoting him on social media”. Others, however, say it will be impossible for any strategy to completely avoid the possibility of prime ministerial mistakes. “It’s almost impossible for the party leader not to be front and centre to some degree,” said Oliver. “If you hide the prime minister that is never going to work.” He added: “It is worth listening to those in the party who believe Labour’s lead is soft and might crumble during the campaign. But in reality for Rishi Sunak to be prime minister after the election, so many things would have to change it feels highly unlikely.”