The winner of the race to become the next first minister of Wales is to be revealed on Saturday.

Whether Vaughan Gething or Jeremy Miles is elected Welsh Labour leader, it will be a historic moment.

If Gething wins and is confirmed as first minister next week, he will become the first black leader of a European country; should Miles be victorious, he will be the UK’s most senior gay leader.

But there will be no time for resting on laurels. Whoever finds himself in the grand first minister’s office overlooking Cathays Park in Cardiff next week has a demanding in-tray.

He will have to unite Welsh Labour after a divisive leadership campaign and prepare to lead the party into a general election. He will have to steer the country through the cost of living crisis and drive up standards in health and education at a time of deep budget cuts.

And there are tricky issues that the outgoing first minister, Mark Drakeford, leaves behind, such as the 20mph speed limit and changes to environmental policy that have led to farmers’ demonstrations on the steps of the Senedd.

Laura McAllister, a professor of public policy at Cardiff University, said the Welsh people would be less interested in the history-making aspect of Saturday’s announcement than the new leader’s approach to the issues that directly affect their lives. “I suspect the Welsh public are more concerned with public policy,” she said.

Labour has governed in Wales since devolution a quarter of a century ago but McAllister said the new leader would inherit a weary party that, if Keir Starmer wins, will no longer be able to blame its problems on the Tories in Westminster.

“Vaughan Gething or Jeremy Miles will have a very different operating climate, less excuses if and when Keir Starmer is prime minister but facing a similarly tight public expenditure climate,” said McAllister.

Gething, who turned 50 on Friday, is undoubtedly the most high-profile of the two candidates and is seen as the slight favourite.

He made history in 2013 when he became the first black minister in any of the devolved nations before rising up the ministerial ladder and has worked as health and, most recently, economy minister.

The path was rocky at times. He was health minister during the Covid crisis and was criticised when he was pictured during lockdown eating chips in a park with his family. He said he had not broken the rules, but “chipgate” was damaging.

This week he had a difficult time at the UK Covid inquiry when he admitted all his WhatsApp messages from the time of the pandemic had vanished when his Senedd phone underwent a “security rebuild”.

His run for leader was hit by revelations that he took £200,000 for his leadership campaign from a company run by a man convicted of environmental offences. Eyebrows were also raised when it emerged that Miles was not eligible for the support of Unite because he has not been a lay union official. Gething received the backing, which was seen as a “stitch-up” by Miles’s supporters. He will have to build bridges with Miles’s backers in the Senedd.

Miles, 52, was brought up in a working-class family in Pontarddulais, Swansea. He has spoken movingly of struggling to fit into the world as a young gay man and joined the Labour party after being dismayed at the damage Margaret Thatcher’s policies caused to mining communities in south Wales.

He went to the University of Oxford and held senior legal and commercial posts in the media sector before coming to frontline politics relatively late. His most recent job has been education minister, meaning it fell to him to explain poor results for Wales in the Pisa assessments. During the Covid inquiry this week he confirmed he had turned on his disappearing messages function on WhatsApp – and said he now wished he had kept them.

Tuesday will be Drakeford’s final first minister’s questions. On Wednesday nominations for the new first minister will take place and the fifth leader of the country since devolution will be installed.