President Donald Trump's former personal lawyer Todd Blanche has been confirmed as US attorney general – the nation's top law enforcement official.

Blanche won confirmation in a 50-49 vote, with Republican Senators Susan Collins and Lisa Murkowski opposing him.

Senator Bill Cassidy was the deciding vote after announcing he believed Blanche was the best option the president would put forward. Washington had been anxiously waiting for Cassidy's decision, due to years of acrimony between Trump and the senator.

The vote brings to an end a lengthy standoff between Senate Republicans and the Trump administration over Blanche, who has served as acting attorney general since April.

All Democrats voted against his nomination to lead the Justice Department.

Some Republican senators had raised concerns about his handling of the release of Jeffrey Epstein-related documents and his role in establishing Trump's $1.8 billion "anti-weaponization" fund.

The fund was planned to provide compensation to individuals who alleged government persecution but critics including Murkowski feared it would go to individuals who were prosecuted for participating in the January 6 attack on Congress.

Blanche eventually pledged to walk back the fund after blowback from Republican senators during his confirmation hearings.

It remains unclear whether the commitment is legally binding or whether Trump could later persuade Blanche, his former personal attorney, to revive a similar scheme under another name.

These issues meant Collins and Murkowski held off on backing Blanche, with the latter citing her lack of confidence in Blanche to "check the worst impulses of this administration".

Murkowski announced on Friday she would oppose Blanche, citing concerns over the "politicisation" of the justice department.

Collins also raised concerns about Blanche's role in settling Trump's $10 billion lawsuit with the Internal Revenue Service (IRS), but said he ultimately trusted Blanche to give the president ​candid legal advice.

"This is not a referendum on President Trump, it is a decision regarding Mr Blanche, in very specific circumstances," said Cassidy on Friday. "All considered, I will vote for Mr Blanche."

Cassidy acknowledged Trump is the ultimate decider on the direction of the justice department, but that Senate confirmation would give Blanche "greater leverage to push for things that should be pushed for."

Cassidy also said he was reluctant to impede the department's work fighting violent crime.

During Trump's second impeachment in 2021, Cassidy voted to convict Trump over the 6 January 2021 Capitol riot. The vote did not pass, and when Trump returned to office, he successfully forced Cassidy into retirement by backing a primary challenger for his Louisiana Senate seat earlier this year.

Blanche was already deputy attorney general when he took up the interim leadership role in April, after Pam Bondi was fired.