Andrew Whitaker: Ed Miliband has enough to worry about without one of his predecessors carping from the sidelines

LABOUR leader Ed Miliband has had a bad week by any measure, with reports of a rift with his brother David and rumblings of discontent on the party's back-benches about his performance.

It's probably fair to say he has a lot to do to win the next general election, but, at the same time, he's managed to unite the party's previously warring Blairite and Brownite factions.

Whatever problems Labour is gripped with at Westminster, there's no question that the party is in much better shape as an opposition than it was when it was last turfed out of power at UK level in 1979 – after which, it engaged in bloody, internecine warfare for years.

Mr Miliband has also managed to pick up on a few key themes, such as proposals to narrow the huge gap that exists between the rich and poor in the UK – a goal that has to be the reason for being of any social democratic or left-of-centre party in an increasingly unequal and unfair world.

However, putting aside the pros and cons of how Mr Miliband has fared as Labour leader, it's worth looking at the behaviour of former PM Tony Blair during the past week.

He used a column in the Rupert Murdoch press to launch an attack on the direction Mr Miliband is taking the party, warning he will only win the next election if will win if he "fights from the centre". Mr Blair also endorsed David Cameron's controversial plans to inject a business ethos into the NHS and education sector south of the Border.

From the day Mr Blair became Labour leader in 1994, and right through his 13-year tenure, he made great play of insisting on iron discipline in the party. His mantra was that any criticism of the leadership could only assist the Tories, as he seized complete control of the party machinery, banning politicians with whom he had differences from running for Labour – most notably the ill-fated decision to block Ken Livingstone's candidature for London mayor.

Yet four years after his departure from Downing Street, Mr Blair showed scant regard for the principle of loyalty to the leadership when he spoke out against Mr Miliband. While it's probably not a concerted attempt by what's left of the ultra New Labour wing of the party to destabilise the Labour leader, he certainly has a right to be unhappy about the comments of one of his predecessors and the potential mischief-making surrounding the leaking of assorted documents last week detailing Mr Miliband's involvement in the old Blair versus Brown battles.

Mr Blair was always quick to pick fights with his own party during his time as leader, whether it was over Clause 4, which committed Labour to common ownership, or the trade union link.

There was also Mr Blair's controversial close relationship with the right-wing US administration of George W Bush. However, for a former Labour leader to attack a successor is a step further, even for Mr Blair.