Want to bet?
Tories will cling on to power as long as possible, its in their DNA and their opposition (individually and collectively) is so insipid they will only go when pushed and maybe not even then! Apart from perhaps the Blair years, (and many considered him Tory Light) the Tories would be considered, and consider themselves, as the natural party of Government in the UK, over the last century.
Collectively the left in the UK should be able to oust the Tories, but individually the parties of the left and those who lean that way, couldn't find their way out of a paper bag, even following the most disastrous Tory premiership in history the opposition couldn't get rid of the Tory PM and it took Tory rebels to accomplish that.
Anyone yearning to live under a far left or even left of centre Government needs to consider moving elsewhere, its very unlikely in the UK in the near future... but hope springs eternal, maybe the new leader of the Lib-dems might have a 'plan'?