The fuss is actually about "Brown the Inert". Why "the Inert"?
1) He didn't cause the crash, but his attempts to fix it didn't work and when it was realised they weren't working he did nothing, absolutely nothing to fix it.
2) When MPs were found to be ripping off their expenses claims, some to the tune of thousands of pounds a year, and when some of the worst offenders turned out to be his friends in the Cabinet, he did nothing, except talk. The more he talked rather than act, the more anger and discontent he caused in the general public (the voters).
Labours popularity dropped like a rock. Then the very people he hadn't fired (rightly) turned on him "for the good of the Party" (and themselves of course) and they resigned from the Cabinet at the worst possible time for Gordon hoping to spark a leadership election. Gordon countered by say that if he went he'd "go to the country" (call a General Election) and if he did that *now* most Labour MPs would lose their jobs <gulp!>. That threat, more than anything else, is what saved him.
So he survived the coup and has now replaced the rebels with his own sycophants. His problem now is that at the next General Election Labour is still going to get a good kicking and most of their MPs will be out on their arses... unless the voting system is changed.
He has the power to do that (in theory anyway) and why wouldn't he. The Lib-Dems have wanted PR for decades - it's the only way they'll get any real power - so they'll support such a move. If the electoral system is changed, a lot more Labour MPs will survive.
Full blown proportional representation is special With PR, each party will be given a representative number of MPs and THE PARTY gets to pick which of their candidates will be chosen. Gordon, of course, will choose his friends rather than enemies and rebels. He will therefore remain leader of the party, surrounded by friends and swinging a lot of power in what will almost certainly be, for ever more, a hung Parliament.
Why "hung Parliament"? because under PR nobody gets a majority, it all becomes wheeler dealing and influence and deals done behind closed doors.
PR == Power to the weak but power crazed.