The resignation of Ms Glennie, one of the world's leading soloists, coincided with the verdict of an Arts Council team asked to examine the future of London's leading orchestras.
The review team, headed by an Appeal Court judge, Sir Leonard Hoffman, has spent the past five months taking 'evidence' from three London orchestras: the London Philharmonic, the Philharmonia and the Royal Philharmonic. The team's recommendation was presented privately to the advisory panel yesterday.
The panel will deliver its verdict to the Arts Council on 15 December.
The Star Chamber exercise was seen as way of directing subsidies from the two 'losing' orchestras towards the third, creating a 'super-orchestra' better able to bid for the world's best conductors and soloists.
The Independent learnt yesterday that a compromise had been discussed by the panel, involving a greater regional role for one of the orchestras. However, indications were that one of the three would shortly face the choice between self-sufficiency or closure.
Many in the world of classical music regard the closure of any of the orchestras as a mistake that would deprive the capital of diversity.
Ms Glennie was appointed to the music advisory panel only five months ago and has yet to attend any of its meetings. The Arts Council regarded her appointment as delivering prestige in difficult times.
In a statement made through her husband, Greg Malcangi, Ms Glennie said the Arts Council plan was a hastily conceived policy which would 'threaten the livelihood of performers today and restrict opportunities for young musicians and the public in the future'.
Sir Peter Maxwell Davies, the composer, has already threatened to hand back his knighthood in protest at the proposed cuts.
The London Symphony Orchestra, resident in the Barbican, has remained untouched by the review. Last year the LSO recieved a pounds 1.1m Arts Council grant.
The Royal Philharmonic, resident at the Royal Festival Hall on the South Bank, received pounds 422,521 from the council; the Philharmonia received a pounds 700,000 grant; and the London Philharmonic a pounds 732,250 grant.
In this week's Budget, the overall arts allocation was reduced by 1.69 per cent.
All three of the threatened orchestras have suffered from falling audiences. Attendances at the Royal Festival Hall are down 29 per cent since 1972.
Another super-orchestra, alongside the LSO, is thought to be the way to reinvigorate classical music audiences. The review debate has highlighted funding comparisons with other leading international orchestras.
The German government gives a pounds 9.32m grant to the Berlin Philharmonic, and the Chicago Symphony Orchestra receives support income of about pounds 8m.