Miliband keeps going off the radar and is in danger of sinking without trace

Inside Westminster: Mr Mudie is a maverick, but he shouldn’t be dismissed by Team Miliband

Some Labour MPs have started to liken Ed Miliband to a submarine. It's not a new metaphor for a politician who surfaces occasionally, makes an impact and then disappears for long periods, as it has been used recently about George Osborne.

It's fine for a chancellor to make a limited number of big interventions and then slip out of view for a while.  But it's not good enough for a prime minister or someone who aspires to his job.  Mr Miliband does well when he surfaces but, to the frustration of many Labour MPs,  is spending too much time in the depths and off the public's radar.

That frustration lays behind the outburst on Thursday from George Mudie, a veteran Labour MP, who posed an important question: if he and his fellow backbenchers don't know where the party stands on welfare, education and health, how on earth can the poor bloody voters? Mr Mudie is a maverick, but shouldn't be dismissed by Team Miliband.  As the economy turns, and the Conservatives unite and recover in the opinion polls,  the Labour leader now needs to be above the surface  all the time. He does not have the luxury of being so well known that he doesn't need to court the voters. Far from it: many don't know him, or what he stands for.

It's not that Mr Miliband is complacent, lazy or lacks courage. Quite the opposite.  He views the election race as a marathon, not a sprint. The Coalition's decision to bring in five-year, fixed-term parliaments, setting the election for May 2015,  has given Labour  an excuse not to show its hand in crucial policy areas. It has also given Ed Balls, the shadow Chancellor, who is keener to keep Labour's power dry until much closer to the election, some muscle in his arm-wrestling with Mr Miliband over the timing of policy announcements. If the fixed-term parliaments law had not been introduced, the media would now be speculating about an election next spring and the two Eds would feel under more pressure to spell out what a Labour Government would look like. The danger for Labour is that it is being defined by its opponents, as the Conservatives portray Mr Miliband as "weak" in every utterance and the party as "same old Labour".

The Labour leader now has an opportunity to deflect both Tory lines of attack. His move to recast the Labour's relationship with the trade unions -- so that union members positively opt into, rather than have to opt out of,  funding the party--  is more radical than he has been given credit for.  It is bolder than Tony Blair's decision to scrap Labour's Clause IV commitment to old-style public ownership, in which only a small section of the party still believed, and so was a pretty emaciated dragon to slay. But perceptions and communications matter.  John Smith, Mr Blair's predecessor, demolished the unions' block votes,  switching to "one member, one vote" in party elections. It was a more radical step than ditching Clause IV but he got less credit than Mr Blair.

Mr Miliband did not pick a fight with Unite and other unions and is adamant that he is not "doing a Blair" by defining himself against his party. To him, that is so New Labour. Equally, he knows he is now embroiled in a battle with the unions he must win. Failure would fit perfectly into the Tory script.

Yet some Labour MPs are worried that the debate over the party-union link, which will run until a special Labour conference next March, will leave the voters cold. They say it could look like navel-gazing, a diversion from the real world "living standards crisis," the issue that will dominate the election. This is territory on which the two Eds are convinced they can win as it will put the focus on the Coalition's record since 2010, making it harder for the Tories to bang on about the record of the previous Labour Government.

We will see more Labour policies next month, in the run-up to and during the party's annual conference in Brighton.  Miliband allies insist he always intended to go positive at this time, after spending the first part of this year neutralising Labour's negatives on the deficit, welfare and immigration to ensure new policies are built on solid foundations. That process was always going to be hard, aides say. Yet I am not sure the task has been completed. Making one speech, even if carefully planned and agonised over for months, does not mean Mr Miliband can say "job done" and move on. Many voters will not even have noticed.  If Mr Mudie is right, very few will have done.

Despite the Labour grumbling and jitters, Mr Miliband is remarkably confident,  and not spooked by the party's shrinking poll lead. Aides insist that reforming the union link is not a diversion from the main event, as it is about bringing ordinary people into the party, which is healthy for politics.

Close allies say the Labour leader will not be buffeted around by events.  He won't  panic. But if his party does, he will have a problem.

Mr Miliband does have a plan.  In his mind, he probably knows what Labour's pledge card will say in 2015 - on issues like universal child care; building one million new homes over five years; cutting energy bills and  limiting rail fare rises. It is time he shared his secret with the rest of us before it is too late.