The "chaotically charming" broadcaster James Naughtie will be leaving BBC's Radio 4 Today show in January, after 21 years of what he calls "setting his alarm for 3am"

In his next stint as special correspondent for Radio 4 with responsibility for "charting the course of the constitutional changes at the heart of the UK political debate" he will begin by covering the 2016 Scottish elections, besides the presidential elections in France and the United States.

Naughtie said: "It was exciting to discover that the BBC and I had the same idea about what I should do next. I'm thrilled to be moving from one dream job to another…And after 21 years, I can turn off that 3am alarm at last."

Jamie Angus, the editor of the Radio 4 show, showered praise on Naughtie calling him a "Today night-editor's dream".

"Out of the office and on the road, Jim was in his element. Insatiably curious and always charming, Jim has a knack of grabbing interviews in a corridor or lift you never thought you'd ever get."

Angus promised the programme would still have plenty of Jim in years ahead as the broadcaster gets back to reporting and writing, his first love.

Naughtie will take on the new role of books editor for BBC News on Radio 4, including a new book review slot on the Saturday edition of Today.

Radio 4 news reader Corrie Corfield tweeted: "I'll miss Jim in the studio. He's chaotically charming. A lovely man and brilliant at those election special 'all-nighters'."

James Naughtie joined the Today programme in 1994 following the death of Brian Redhead. Since then he has interviewed US presidents and every British prime minister since Margaret Thatcher onwards.

He infamously hit the headlines five years ago over an embarrassing slip over the name of then culture secretary Jeremy Hunt when he replaced the H with a C.

In an off-the-cuff apology to Radio 4 listeners, Naughtie said. "All I can say is that occasionally in live broadcasting these things happen", it went. "And, er, I'm very sorry to anyone who, er, thought it wasn't what they wanted to hear over breakfast. Neither did I, needless to say."

There is speculation over who will replace him, with the BBC's political editor Nick Robinson, recovering from a lung cancer surgery, believed to be the frontrunner for the role.

The Left bias

Along with the accolades, the net also saw a fair share of criticism of Naughtie with tweets from the former Ukip MEP Godfrey Bloom calling him "everything that's wrong at the BBC" and a yes-man with "not a single original thought".

The Guardian website saw readers declaring that "they've finally cleared out their last Left-winger from the Today programme".

Much of the less flattering comments were centred around this left-leaning and alleged Labour bias since the 1990s. In a major slip Naughtie referred to the Labour government as 'we' in an interview during the run-up to the 2005 general election.

"If we win the election, does Gordon Brown remain Chancellor?" he asked. Though he immediately corrected himself, Tories seized on the remark as evidence of pro-Labour sympathies.

The son of two teachers, Naughtie who grew up in Rothiemay, near Aberdeen, spent four years in the 1980s as a political reporter for The Guardian, before joining the BBC in 1988.