Leyton Orient have confirmed Russell Slade has handed in his resignation to club ahead of a potential move to Cardiff City.

The 53-year-old is as short as 1/5 with most bookmakers to take over at the Championship side after the parted company with Ole Gunnar Solskjaer.

The Bluebirds had made three approaches for Slade, who was the fourth longest serving manager out of the 92 professional English clubs, last week, but all were rejected by the Brisbane Road side, and that has left Slade with very little choice but to resign as O’s boss if he wanted the opportunity to take the job at the Welsh club.

And an official club statement confirmed that they had received the letter of resignation from Slade, and are currently ‘studying the file’ having rejected a fourth approach from Cardiff City.

The statement read: “The Chairman and the CEO of Leyton Orient have received a resignation letter from Russell Slade a few minutes ago. This has not happened by chance after the Club rejected this afternoon, a proposal from the General Manager of Cardiff City regarding the transfer of Russell Slade. The lawyers of the Club are now studying the file.”

Former Chief Executive Matt Porter tweeted his thanks to Slade, which is the biggest indicator at the moment to suggest his offer of resignation will be accepted.

Porter said: “Probably the best decision I ever made as #LOFC CEO was to recommend we appointed Russell Slade. A pleasure to work with and a great manager.”

For Slade, this will be the biggest test of his managerial career, having yet to experience management in the second tier of English football.

After last night’s 1-0 home loss to Sheffield United in the Capital One Cup, Slade said: “Everybody wants to better themselves, especially when you’ve been in League One for a few years and come so close in May to getting ourselves in that position.

“We were a penalty kick away from the Championship. It’s frustrating. It’s a big club and it will be a big job for somebody that eventually ends up with it.”