At the last general election, YouGov (with The Sun and The Sunday Times) began a programme of continuous daily opinion tracking, including a new tracker for the UK, ‘Government approval’. Each day we not only measure voting intention; we also ask respondents ‘Do you approve or disapprove of the government’s record to date?'

Last week Tim Montgomerie wondered: Which number matters more, Labour's rather poor showing (at this stage of the electoral cycle) at just 6% ahead of the Conservatives (as it was when he asked the question), or the government's current trough of minus 31% approval?



Screen Shot 2012-04-17 at 07.14.03The first graph shows voting intention. The second graph shows the conventional voting intention lead of Conservatives over Labour, together with the Coalition lead (being Con plus LibDem minus all the rest combined), and Government Approval. The data is monthly aggregates from July 2010 until last month, each point representing at least 20,000 interviews. As we would expect, while the Conservative lead correlates strongly with GovApp, the greater correlation is between GovApp and the Coalition lead over the combined Opposition.

This close tracking does not make GovApp redundant. On the contrary, it provides a telling additional measure: GovApp sinks much further than the Coalition's lead in voting intention – the fact that the two numbers were once identical and are now far apart tells us that many more people have lost faith in the government than are currently willing to actually switch parties. The distance between these two trackers defines the risk (for the coalition parties) and the opportunity (for the opposition parties).

Looking at the change in voting intention since July 2010, we see that the Conservatives and the LibDems have lost around 6% each, while Labour have gained nearly 7% and 'others' have gained just over 5%. The most likely explanation is obviously that disaffected Tories have switched to UKIP and disaffected LibDems have moved to Labour.

That doesn't necessarily mean to say the same split holds true for the disapprovers who have so far remained loyal. In the future, we should ask some follow-ups to this group: how close are you to switching your vote, and if you did, which party would you be most likely to switch to? What would need to happen to make you take that step?

Without this extra data, we can't be sure whether the biggest risk to the Conservative vote is from Labour or UKIP. More votes have been lost (and might be regained) from UKIP; but one might guess that from here on, the greater part of potential defectors would go to Labour but are held back by Ed Miliband, who still trails Cameron in the good job/bad job ratings by 12%. It's pure speculation, until the additional work is done.