The negotiator role would also involve acting as an EU “sherpa” — representing the prime minister in negotiations with the bloc — and leading talks with Brussels on a proposed security cooperation agreement.
It will also include dealing with existing Brexit agreements and upcoming changes to EU border rules that aim to digitalize entry to the bloc and to impose a fee for Britons starting next year, the so-called EU Entry/Exit System.
The move to appoint a new negotiator comes after Starmer visited Brussels last month for the first time since becoming prime minister, where he met with European Commission President Ursula von der Leyen.
The two agreed to explore stronger ties on the economy, energy, security and resilience.