There has been much comment in the media recently about Ed Miliband's leadership of the Labour Party. This month's Ipsos MORI Political Monitor showed half (49%) of Britons thought Labour should change their leader before the general election next year, and polls from Ipsos MORI and other pollsters have shown his ratings suffering for some time. But how does he compare historically to other leaders of the opposition - and what does this tell us about his chances with ten months to go until the general election?
We have looked back through our historical data to compare the scores of Mr Miliband and his party on various measures with previous opposition leaders, around one year out from a general election, back to Tony Blair ahead of his victory in 1997. The exact timing of the polls in comparison to the subsequent general election differs, as obviously does the political context. Ed Miliband is competing with a far stronger UKIP and a more popular prime minister than Tony Blair or David Cameron had to face, for example, while Iain Duncan Smith's ratings are of necessity further out from the 2005 general election, being ousted as leader in 2003. The fact that we now have a coalition government also adds to the uncertainty. Our methodologies have also changed slightly on some aspects - for example, our headline voting intention figures since 2002 have been based on those saying they are certain to vote, with previous figures based on all giving a voting intention. However, it is an interesting comparison nonetheless, and gives at least some indication of the current state of play in comparison with previous elections.
Mr Miliband scores poorly for personal readiness to be prime minister. Just under a quarter (22%) think he is ready to be premier, steady from when we asked in April 2013. He is seen as more ready than William Hague was a year out from the 2001 election (18%) and Iain Duncan Smith in the months leading to his resignation (16%), but lags Michael Howard (31%) a year out from his defeat in 2005. The two election winners as opposition leaders, Tony Blair and David Cameron, both had far stronger figures on readiness for power, on 56% and 43% respectively.
A similar pattern can be seen on personal satisfaction scores. The proportion satisfied with Ed Miliband this month is identical to that for William Hague in June 2000; indeed, the chart of net satisfaction we release each month shows an increasingly similar pattern for Mr Miliband to that of Mr Hague's Conservative leadership. He has marginally higher satisfaction than for Michael Howard ahead of the 2005 election.
Again Ed Miliband fares poorly in comparison with prime ministers in waiting, Messrs Blair and Cameron. This is particularly so in satisfaction among the party's own supporters - while Mr Blair enjoyed 71% satisfaction among Labour supporters in 1996 and Mr Cameron 81% among Conservatives in 2009, only half (49%) of Labour supporters are satisfied with the performance of Mr Miliband with less than a year to go until the general election. Only Iain Duncan Smith had lower satisfaction among his own supporters (36%) - this in the final month of his party leadership.
It is not only Mr Miliband personally who suffers by comparison here, however. Just under a quarter (23%) think Labour has the best team of leaders, leaving the current shadow frontbench ahead of the teams of Messrs Howard (20%) and Hague (13%), but some way behind the teams of David Cameron (39%) and Tony Blair (35%).
And on clarity and unity around policy, Labour again fall short currently - though this is particularly affected by the recent emergence of UKIP as a political force. They are currently on 17%, far from the 30% of Mr Cameron's opposition in 2009, though ahead of the low of 9% under William Hague.
The current Labour Party as a whole appears to be moving in the right direction, however - just over a third (35%) now consider them ready for government, up from 29% last year. This is again better than William Hague, but in line with Michael Howard's Conservatives (35%), and lags the opposition parties of David Cameron and Tony Blair - though is less of a gap to the 2009 opposition of Mr Cameron (41%) than on other measures. Blair's Labour of 1996 have by far the biggest score here (58%).
All-importantly, Mr Miliband's party still have a lead on voting intention - and the Conservatives haven't been ahead in a single Ipsos MORI Political Monitor poll since 2011. While less impressive than the leads of Cameron and Blair at similar points in opposition, it bodes far better than the figures under Messrs Hague, Duncan Smith and Howard.
Where does Ed Miliband sit, then, in comparison with other recent leaders of the opposition? On some measures, the leader with the most similar figures is Michael Howard. Ed Miliband scores better than William Hague and Iain Duncan Smith, but this is hardly comforting news. However, he has also achieved what only Messrs Blair and Cameron of the leaders mentioned have managed - a sustained, long-term poll lead (albeit one that has narrowed in recent months). So for every set of figures that can't compare to the opposition leaders who have become prime ministers, he has already met the precedent in this regard.
And reassuringly for Mr Miliband, while many may want him out, there is no obvious alternative cited by those who want a change in the Labour leadership. Two thirds (68%) of those who think Labour should change their leader answer either 'don't know' or 'no-one' when asked (unprompted) who they would prefer. The most-mentioned alternative is his brother, David Miliband, who is not currently involved in British politics. Without such an alternative, it would appear any leadership change is unlikely. And in any case, it is far from clear that a change in leader and the disunity associated with such a process would be beneficial even were an obvious alternative in place - especially at this point in the electoral cycle, with the general election less than a year away.
So the picture - as with much else ahead of the 2015 election - is a complex one, with no easy answer from the precedents we do have. Ed Miliband's personal ratings are poor, it's true, but his party remains in front - just - under his leadership. And as we mentioned, this doesn't exist in isolation - the Conservatives have a lower vote share, for example, than Labour had a year before their repeat election victories in 2001 and 2005. The lessons of history, in this case, do not point to a single future.