John Mann tweeted in response to a number of front and back benchers who have recently called for the Labour leader to be clear in setting out the party's policies.
Shadow health secretary, Andy Burnham, was the latest after insisting Miliband has until next spring to spell out his ideas in a way that "captures how people are feeling and thinking".
This came after veteran backbencher George Mudie said the party was "hesitant" and "confused", sentiments echoed by his colleagues Geraint Davies and Graham Stringer.
The Tory party has seized upon the unrest as a sign that even Miliband's own party has no faith in his leadership.
Conservative chairman Grant Shapps said: "This shows that even senior members of Labour's top team think Ed Miliband doesn't have what it takes to stand up for hardworking people.
"His lack of leadership and his lack of ideas shows he's a weak leader of a party that just hasn't changed. It's the same old Labour Party and hardworking people would pay the price of its failure to face up to the mess it created."
Burnham, who ran against Miliband in the Labour leadership battle, has insisted this is not the case.
He said: "No, this isn't a criticism of Ed ... I'm making it a criticism of modern politics."
Speaking on BBC Radio 4's World this Weekend Stringer said there was no challenge to Miliband's leadership but added: "The real worry is the almost deafening silence there has been from the shadow cabinet in a time of the year which is traditionally a ripe time for the opposition to attack the government.
"While the government are on their holidays and thinking about other things, the opposition has always used that as a way to put policies into the public's mind and to have a go at anywhere the government has failed.
"I think the party is genuinely worried about the lack of activity in the shadow cabinet."
He added there was a "lack of coherence and cogency" in Labour policies.
"It's not quite clear what our policies on welfare are, what our policies on housing are, what our policies on education are.
"Although I don't expect Ed Miliband and other members of the shadow cabinet to write out precisely what is going to be in our manifesto in 20 months time, I do expect the public should be told, and the party should be able to support, very clear and coherent policies."
He said the unity that had been portrayed within the Parliamentary Labour Party since the election was "a bit of a mirage" because there were a "lot of different views and there is serious concern across the parliamentary party about what our policies should be".
Report suggest Miliband is planning a reshuffle before Labour's autumn conference, and Stringer suggested a prominent figure such as Lord Peter Mandelson could return to play the key election strategy role vacated by Tom Watson.
"There's no doubt that when Peter Mandelson held that kind of position in the past the Labour Party was more cogent and coherent in getting its message across," he said.
"Whether a) he is willing or b) is the right person now, I don't know. But somebody of his abilities needs to be in that position."
Responding to Stringer's concerns, Ashworth said: "On housing, we have talked about the fact that we want to build more housing. On welfare, we want to introduce a job scheme to get people back to work.
"Do we need to work harder to get our messages across? Of course we do."
He added: "I entirely concede that over the next 20 months as we run up to that 2015 general election it is now time for us to start coming out with further radical, bold, eye-catching policies."
With Labour activists set to gather in Brighton next month, Ashworth said: "I would hope that at the party conference in a few weeks time we give more details of the direction of travel, because we have got 20 months - it's not an election around the corner.
"It's important that we work on these policies but in order for our policies to command the confidence of the British people, the British people need to be reassured that they are fully costed and that we understand the financial situation that we will inherit."