Who is Labour's Keir Starmer, the new leader of Britain?

• The U.K. elected its first Labour prime minister in 14 years.
• Keir Starmer takes the top job from Rishi Sunak, Britain's fifth consecutive Conservative prime minister.
• The 61-year-old human rights lawyer-turned-politician has had a rapid ascent after entering Parliament less than a decade ago.

LONDON — Britain elected its first Labour prime minister in 14 years, with a landslide victory for the opposition party during the July 4 elections.

Keir Starmer takes the country's top job from Rishi Sunak with projections suggesting his left-of-center party could have a majority of around 170 seats.

Starmer has had a rapid political ascent after entering the U.K. Parliament less than a decade ago. But many Britons still know little about the man who has positioned himself as the country's change candidate.

CNBC takes a look at the U.K.'s new prime minister and his platform.

Human rights lawyer-turned-politician

Starmer was born in 1962 in London to a father who worked as a toolmaker and a mother who was a nurse.

The 61-year-old has often referenced his modest beginnings as a point of connection with British voters and says his mother's lifelong battle with a severe illness gave him a deep gratitude for the National Health Service (NHS).

Starmer was the first in his family to go to university, studying law at the University of Leeds. After postgraduate studies at the University of Oxford, Starmer began working as a barrister — or British trial attorney — in 1987, taking on high-profile cases, including against Shell, McDonald's and former Conservative Prime Minister Margaret Thatcher's mine closures.

Starmer also served as a human rights advisor during former Labour Prime Minister Tony Blair's landmark Northern Ireland Good Friday Agreement.

In 2008, a year after marrying his wife, Victoria, Starmer became director of public prosecutions, putting him at the head of the U.K.'s Crown Prosecution Service.

Starmer was knighted in 2014 for his services to criminal justice and was elected to Parliament the following year, serving as immigration minister and Brexit minister for the opposition.

In 2020, he was appointed Labour leader and instigated a major overhaul of the party after the resignation of Jeremy Corbyn, who led the faction to a record loss in the 2019 election.

Pro-business, pro-reforms, pro-EU

In his 2024 election campaign, Starmer touted a "decade of national renewal" for the country following what Labour has described as years of spending cuts and falling living standards under the Tories.

In the party's election manifesto, published last month, Starmer outlined spending measures to create a new publicly owned energy company, reduce NHS waiting times, build new homes and renationalize rail services.

But he also positioned himself as staunchly pro-business, continuing his yearslong charm offensive on traditionally right-leaning voters with plans for "wealth creation" and a National Wealth Fund.

"Economic growth and social justice must go hand in hand," Starmer said at the launch event of the manifesto.

Labour has outlined five long-term missions if it comes to power: drive economic growth, invest in green energy, overhaul the NHS, create safer streets and deliver "opportunity" through a new skills agenda. To aid these goals, Starmer is planning a radical shake-up of government ministries, Labour officials told the Financial Times.

Starmer, who voted for the Remain campaign not to depart the European Union in the U.K.'s 2016 EU referendum, has also pledged to improve the "botched" U.K.-EU deal, including in areas such as trade, research and security. However, he has insisted there is no case for Britain to rejoin the bloc.

Public image problem?

Despite his change agenda, Starmer is seen by many as an establishment figure, lacking the charisma of other politicians. A YouGov poll from earlier this year ranked him behind Reform's Nigel Farage in terms of public popularity — and his rating fell further among younger voters.

Critics have also questioned Starmer's core values — for example, remaining in Corbyn's top team even as the party leader faced accusations of antisemitism within Labour. Starmer later suspended Corbyn from the party. Others have accused him of betraying the left by courting business leaders and dropping pledges such as abolishing university fees.

After a bumpy few years for British politics, though — with three different Conservative prime ministers in 2022 alone — Starmer's supporters are championing him as a neutral figure of stability after a period of significant political upheaval.

— CNBC's Katrina Bishop contributed to this report.