London Welsh have been removed from English rugby’s professional ranks and will immediately forfeit their place in the Championship.

The Rugby Football Union has declared the club’s position in the second-tier Championship “untenable” after it failed to convince England’s governing body of a sound future financial footing. London Welsh fell into liquidation in December, before being granted a temporary licence that expired on 21 January.

A new board was challenged to provide evidence of funds to pay creditors and clarity on a new business plan, but RFU bosses were left unconvinced.

“It is deeply regrettable that we should arrive at this point, but with London Welsh in liquidation and unable to satisfy conditions to compete in The Championship as a professional club, participation in the competition became untenable,” the RFU chairman, Andy Cosslett, said. “We know this will be an extremely disappointing day for everyone connected with London Welsh, including players, staff and supporters, and the sadness at the loss of this club from the professional ranks will be shared throughout the game.”

All of the club’s remaining fixtures and results have been expunged and there will be no relegation from the Championship as a consequence. The league will still be made up of 12 teams next season including the team promoted by winning National League One.

In a statement, the club said: “London Welsh is extremely disappointed by the decision of the RFU to expel the club from the Championship. The club has worked very closely with Nigel Melville, Ian Ritchie and Angus Bujalski of the RFU for a number of months to meet the criteria for a permanent licence, and the new company believes that it did satisfy all of the conditions required in RFU regulation 5 and the insolvency protocol. The club will begin dealing with the ramifications of (Tuesday’s) announcement before deciding whether to respond further.”

London Welsh became one of the amateur domestic game’s glamour clubs in the 1960s and 70s, boasting Wales stars like John Dawes, JPR Williams, Gerald Davies and John Taylor.

But the Old Deer Park side have struggled to move with the times and falling into liquidation in December has now proved fatal to their professional status.

An RFU statement read: “Following the appointment of liquidators in December 2016, a temporary licence was granted by the RFU to London Welsh, via a ‘Phoenix Entity’, to enable participation in The Championship.

“The licence expired on 21 January 2017. The conditions required by the RFU regulations to enable London Welsh to continue to participate in the competition following the expiry of the temporary licence have not been met – despite the RFU granting two extensions to deadlines – and, with regret, London Welsh will no longer be granted permission to play in the Championship for the remainder of this season and beyond.”