YouGov's poll for the Sunday Times suggests that the three men could have bright futures.
The poll suggests that the three politicians are those most favoured to lead their respective parties if their respective leaders step down.
The questions asked:
If [current leader] were to step down as leader of the [name of party], which of the following do you think would make the best leader?
For the Conservative party, 22% of all respondents said they would prefer Boris to lead. In second place, 12% said Theresa May. 4% said George Osbourne. However, in better news for Mr Johnson, when just looking at those intending to vote Conservative, 33% said they would want him to be the next leader, whilst in second place, once again, came Theresa May on 17%. Additionally, 10% of Conservative voters said they would prefer George Osbourne.
If David Cameron loses the keys to Number 10 then there will be a leadership election within the Tory party. With Boris Johnson likely to win in his constituency there is a chance that he could win a leadership election, and perhaps become Prime Minister in the long run.
The other Miliband brother - David - departed from politics back in 2013. He did once come nail bitingly close to leading his party in 2010, but Ed Miliband won the leadership contest. Despite his departure from British politics almost two years ago, 18% of all respondents said he should lead Labour if his brother stepped down. Ed Balls came second with 7%.
As for just respondents who said they intended to vote Labour, 23% chose him, putting him ten points ahead of Ed Balls on 13%.
It’s unlikely that David Miliband will be the next leader of the Labour party, however, he could come back to British politics in the distant future.
If the Liberal Democrats end up not being participants in the next government then it is likely that they will need a new leader to take them forwards.
The poll suggests that 15% of all respondents think that Cable should lead the party after Nick Clegg departs. Next came Danny Alexander, with 10% thinking he should lead the party. As for just those intending to vote Lib Dem in May, 21% said they would like to see Vince Cable in charge, whilst 13% said Danny Alexander.
Overall, May will probably result in at least one change of leader after the election. If the Liberal Democrats are excluded from coalition then it is likely that two parties will need a change in leader.
The poll gives an indication as to which new leader people prefer, but with 2015 being incredibly unpredictable who knows which way the parties will go.
YouGov quesioned 1578 GB adults between the 22nd and 23rd of January. The full results can be found here.