The last remaining original panel member on the Scottish Child Abuse Inquiry has resigned, prompting further concerns from abuse survivors that it is in crisis.

Glen Houston's resignation means that all three of the launch team for the SCAI have now quit. Professor Michael Lamb resigned in June last year amid claims about Scottish Government interference in its work, followed by the then Chair Susan O'Brien QC.

Ms O'Brien stood down before the conclusion of a formal statutory process‎ which may have led to her removal and is currently suing the Scottish Government over loss of earnings and damage to her reputation.

David Whelan of the charity Former Boys and Girls Abused of Quarriers Homes said: "We still fully support the inquiry but it is important that it is stable and doesn't lurch from crisis to crisis."

Mr Swinney said he had accepted Mr Houston's resignation due to "a change of circumstances in his working life", after he accepted two jobs which were potentially incompatible with working on the independent inquiry. He said that like his former colleague, Professor Michael Lamb, he would not be replaced.

Mr Houston said: "Due to a change in priorities in my working life, last year I applied for positions as a non-executive director to the boards of two public sector organisations, the Northern Health and Social Care Trust and the Disclosure and Barring Service. I have now been successful in those applications and the appointments have been made.

“Lady Smith and I have discussed the potential that at some future time, a perception of conflict of interest may arise between these appointments and my work as a panel member on the Scottish Child Abuse Inquiry.

“After careful consideration of both the time commitment required to fulfill these new roles and the potential, however small, for perceptions to arise of conflict of interest, I have tendered my resignation to the inquiry."

He said the inquiry had made significant progress and he remained fully supportive of its work.

Mr Swinney added: "I know this was not an easy decision for him to reach, but he can be very proud of the contribution he has made to the establishment of the Child Abuse Inquiry and to ensuring its continuing progress.

"Following consideration of the matter, at this stage in the inquiry’s work, I have decided not to appoint a successor. Lady Smith will continue as chair of the inquiry and as sole panel member.”

Lady Smith said: “Mr Houston has made a valuable contribution to the work of the Inquiry during his time as a panel member and I am very grateful to him for his support. I fully understand his decision and wish him well in his new ventures.

“The important work of the Inquiry continues as normal and we would encourage anyone who has relevant information, whether they have been abused themselves or know others who have, to get in touch.”