Tessa Jowell: 'Brothers must show they are united'
In the first week, on the basis that the only certainty is that the leader will be called Miliband, the most important thing is the demonstration of reconciliation between the brothers. This is a vitally important signal for the Labour movement, that whichever Miliband wins, the other, and their supporters, will rally round so there is not a shred of division. This should be the inspiration for delegates to the Labour conference to go back to their constituencies to get ready for the problems ahead. In the longer term, the leader's task is to define how we take on the Con-Dems and rally the party behind a developing vision for the progressive future that recovers the ground we lost at the last election.
Tessa Jowell is the former Secretary of State for Culture
Dave Prentis: 'Tell voters cuts are not the only course'
Take on the Coalition with a clear alternative to devastating public service cuts. The public is buying the mantra that the cuts are a necessary evil, not an ideological choice. The new leader must challenge that assumption and focus on fairer ways of getting the economy on track. They must show that the party represents the old, poor and vulnerable by robustly challenging Government policies that threaten those most in need. They will have to work hard to unite the party and demonstrate there will be less top-down control and more listening.
Dave Prentis is general secretary of the public sector union Unison
Tim Montgomerie: 'Use poll bounce'
Gordon Brown's successor will receive oodles of attention next week. Unless blood is spilt by the losing Miliband's supporters, Labour should enjoy a big poll bounce by the time it leaves Manchester. Its lead will widen considerably thereafter. The Coalition is entering a valley of extreme unpopularity as it cuts waste from the bloated state and faces a backlash from the unions that scarred Tony Blair's back when he attempted much more modest public sector reforms.
Labour's new leader must resist the temptation to coast during this period. Unless the Coalition falls apart – and this week's upbeat Liberal Democrat conference suggests it will not – Labour needs to prepare for a close election, fought against the backdrop of a growing economy and when George Osborne will be arguing that his medicine restored the sick economy to health.
Labour may need their own coalition with the Lib Dems. Working towards a red-yellow government in Holyrood after next May's Scottish elections would be a sensible start. The new leader's strategy must open the door to Liberal Democrats, not shut it in their face. The cuts debate will be over by 2015. The new Labour leader must fashion a policy programme that excites Liberal Democrats and their supporters.
Tim Montgomerie is the editor of ConservativeHome
Shami Chakrabarti: 'Support freedoms'
Start as you mean to go on with a clear and immediate repositioning of the party on fundamental rights and freedoms. Many of its natural voters and activists lost faith in Labour as it morphed from a movement of universal suffrage, anti-discrimination and fighting miscarriages of justices to the party of universal snooping, stop-and-search without suspicion and punishment without trial. They were ashamed by the "journey" from Tolpuddle to Guantanamo Bay. Learn from the Conservatives' long opposition. Bashing asylum seekers and young people in trouble can seem like short-term populism until people tire of "the nasty party" and look for something more positive to vote for.
This doesn't require a total trashing of recent past policy. The Human Rights Act and equality legislation provide vital protections for the vulnerable against the powerful. Honour these values in thought and word and deed. The Coalition's counter-terror review is an early test. Show real statesmanship and refuse to play politics over this issue. Say that indefinite house arrest without charge is Burma not Britain. Confound the Government and impress your sceptics. Call for the shameful system of "control orders" to be scrapped.
Shami Chakrabarti is director of the human rights charity Liberty
Chris Mullin: 'Use the experience at your disposal'
What to do in the first five days: persuade Alistair Darling and Alan Johnson to remain on the front bench. We need to call a halt to this cult of youth. Credibility and experience are what counts, not an ability to chant the slogans of the hour. A sense of humour helps, too.
What to do in the first five weeks: Once Boy George and his Lib Dem playmates have announced their plan for laying waste to the public sector, there are going to be some open goals to kick at. The lie that the state of the economy is all Labour's fault needs to be firmly rebutted. Labour then needs to provide a constructive, jargon-free alternative to the proposed scorched-earth policy. On no account, however, pretend that there is no need for any serious cuts. That way lies ruin.
You might also want to flag up the greatest challenge facing the human race: how to live sustainably.
Chris Mullin was a Labour MP for 23 years. Decline & Fall, the second volume of his diaries, was published earlier this month
Anthony Seldon: 'Forget past glories and plan the future'
Labour badly needs a leader who can restore its moral authority and purpose which it lost as New Labour. This party is about fairness and goodness, or it is about nothing. Because it lacked a clear plan of action in 1997 and made it up as it went along, the unrivalled opportunities were squandered. Not for another 50 or more years will Labour enjoy the electoral success that came in 1997, 2001 and 2005.
The party must prepare itself for power in coalition or with small majorities, which traditionally it has not handled well. Its programme must revolve around quality of life issues, and ensuring that the wellbeing and happiness of all members of society are protected and extended, even when that means taking on the status quo.
It means a rededication to the public realm and to civic engagement, not in the old top-down, socialist and trade union sense, but with the energy coming from the bottom up. The Labour Party of MacDonald and Attlee, of Wilson and Callaghan, and even of Blair and Brown, should be placed light years away. The 21st century is utterly different, in its technology, economy, political and social realms, and the Labour Party under its new leader needs to enter it boldly and decisively.
Anthony Seldon is the author of Blair Unbound. His next book, Brown at 10, is published in NovemberReuse content