He's toast. If a Prime Minister can only attract the support of 49 of his own MPs (out of a total of 370) surely it is only a matter of time before the removal men come-a-calling. Full story HERE on the BBC website.
I'd sum up his position in one word. Unassailable*.
* For older readers, Margaret Thatcher described Nigel Lawson as 'unassailable' a matter of days before he resigned in 1989.