After being cheered by Monday's (unreliable) SNP/Panelbase poll on Scottish independence, which put the Yes campaign ahead for the first time since August 2011, Scottish nationalists have woken up to the grim news that support for separation has fallen to its lowest level this year.

A new TNS BRMB poll shows that just 25% would vote for independence compared to 47% who would vote against it. The survey is further evidence of why the SNP poll should be treated with scepticism. Those polled were first asked whether they thought Scotland could be "a successful, independent country" and whether they trusted the Scottish government or Westminster to take "the best decisions for Scotland". It's likely that both questions nudged people towards supporting independence in the final question.

Every other poll in the last two years has shown the No campaign ahead by a convincing margin and the TNS BRMB survey and last week's YouGov poll (which put the No camp ahead by 59-29) suggest that trend will continue.

If there is any consolation for the Yes campaign, it's that 28% of voters are undecided, up from 15% in February, but it would need to win over 79% of them to close the gap with the No camp. At present, even if, as Alex Salmond recently told the NS, "This is the phoney war. This is not the campaign. I went into an election [for the Scottish Parliament] in 2011 20 points behind in the polls and ended up 15 in front. The real game hasn’t even started. We are just clearing the ground", that is looking like a near impossible task.