Ed Miliband is a b****** - and that's a good thing Westminster bubble residents see his alleged filial betrayal back in 2010 as a defining moment, one way or another. As a former supporter of David's, I was one of them. At first I was equivocal about this challenge to my preferred candidate; relaxed, even. Then, as the end of the absurdly prolonged contest approached, I became more nervous. By the day of his victory at Labour conference in Manchester that September, I had convinced myself that Ed was a ruthless bastard. The difference between then and now is not that I've changed my mind; it's that I no longer see that assessment as negative. One of his earliest acts as leader - within hours of his coronation, in fact - was to inform Nick Brown, chief whip under Gordon and assumed to be ready to continue in Opposition, that his services would no longer be required. The act was risky, brutal and decisive. As was Ed's unexpected but entirely correct decision to dispense with the absurd requirement on Labour MPs to elect the shadow cabinet. On Falkirk and the related vexed question of trade union influence in the party, Ed's response has been thoughtful and far more radical than anyone expected. It's now the accepted wisdom that it was "the unions" that won it for Ed. Wrong. It was Ed that won it for Ed. He was hungrier than David, more impatient. If David had shown a little of the steel his younger brother clearly possesses, and shown it earlier, he would have followed through on his various thinly-veiled threats to Gordon Brown's unhappy premiership. Instead he waited, bided his time while Labour sailed to certain defeat at the 2010 general election. David might not have triumphed, of course. But that's politics for you. It's risky, and if you can't take risks, you should perhaps consider an alternative career. If Ed might not appreciate my comparing him with Mrs Thatcher, he might be more open to a second comparison: the upstart Tony Blair faced down his erstwhile mentor and senior partner, Gordon Brown, to win the leadership in 1994. Gordon had spent so long as the heir apparent that he and those round him didn't seem to notice that his star had been eclipsed, at least for the next decade or so. It's not a completely satisfactory analogy: Tony was the favourite from the start, and Gordon decided not to stand against him. More importantly, as Opposition leader, Tony was up against an ageing, discredited government; Ed has a relatively harder job, opposing the first peacetime coalition for nearly a century, and one that had just come to office when Ed won the leadership. Sure, Britain needs leaders who can communicate and "relate" to ordinary voters (whatever that actually means). But the real test of leadership is about far more than that: it's about courage. There's no courage in taking a stand you know will be supported, in entering a contest where you're virtually guaranteed to win (or guaranteed to lose). Lesser men than Ed Miliband would have buckled under the weight of expectation and carping, lazy criticism from the commentariat and various unattributable briefings from colleagues. It's a mark of the strength of Ed's leadership abilities that he doesn't panic, doesn't overreact, doesn't blame others or throw his toys out of the pram when things aren't going perfectly. His strength of purpose and his conviction should encourage every opponent of this government that its days are indeed numbered. Having recently resigned from the front bench, I cannot be accused of trying to curry favour with the man I voted against in 2010. I say all this for one reason only: it's true. The kind of steel within Ed Miliband is what the Tories needed nearly 40 years ago and it's what our party needed in 2010. We still need it today. And by 2015 we'll need it more than ever. Tom Harris is the Labour MP for Glasgow South