Will Ed join David Miliband as he returns to the limelight?

For the first since he lost the Labour leadership to his younger brother, David Miliband is to take a small step back into the limelight.

The former Foreign Secretary has been virtually absent from the political stage for the last 13 months, saying he did not want to divert attention from Ed Miliband's early days as leader.

Now David is returning and venturing into the potentially sensitive subject of what policies the party should pursue to win over wavering voters. Miliband senior and his ally Jon Cruddas, the Dagenham MP, are to stage a series of Commons seminars entitled "Labour's Future".

They have asked Ed to attend – and even to speak – but the Labour leader has yet to decide whether to accept the fraternal offer. A spokesman said: "We are happy to have been invited, but have not yet made a decision."

If he accepts, it will be the first time the pair have appeared on a public stage since the 2010 Labour conference in Manchester, where the result of the leadership contest was announced.

David limited his presence at this year's conference to a brief appearance at a fringe meeting before leaving for a conference about China in the United States and missing his brother's keynote speech. His supporters explained that he would have provided an unwelcome distraction to Ed if he had remained longer. For the same reason David turned down the offer of a Shadow Cabinet post in last week's reshuffle.

The seminars, which will also involve Matthew Taylor, the head of the Downing Street policy unit under Tony Blair, are designed to stimulate debate within the Parliamentary Labour Party at a time when Ed Miliband is struggling to make an impression on the public. Labour has failed to pull clear of the Tories despite the state of the economy.

Relations between the brothers have been chilly over the past year, but senior Labour sources claim the "psychodrama" has now ended and that the Milibands are ready to work together again publicly.