The prevailing expectation is that he will become prime minister

The Labour Party's victory in yesterday's by-election in Makerfield heralds a dramatic shift in British politics. According to "prevailing expectations," party leader Keir Starmer is poised to assume the role of Prime Minister. This electoral outcome, although a by-election, sends a strong message of support for the Labour Party and its leader. Analysts believe this victory could pave the way for a general election and a change in government in the UK. Details on how this change will affect the country's policies and what the new government's priorities will be will be subject to further analysis. Starmer's government is expected to introduce new policies in key areas such as the economy, social issues, and foreign policy.

This news indicates a potential change in government in the UK, with Keir Starmer as the likely future Prime Minister.