Welsh Liberal Democrats are confident they'll have the backing of the party's leadership for their bid to block regional pay plans.
'Regional pay' is the shorthand used to describe controversial suggestion that public sector workers should receive different salary levels depending on where they live in the UK. That's widely seen as meaning nurses, doctors, teachers, police officers living in expensive places like London and the South East of England would be paid more than people doing the same job but who live in areas where property prices are lower, such as Wales.
Party members from Wales want their colleagues in government at Westminster to rule out any moves to introduce the controversial changes. If they succeed, Kirsty Williams hopes it'll send a clear message to voters worried about Lib Dem decisions in coalition government. Here's what she told me:
That last exchange is particularly important because as Chief Secretary for the Treasury, Danny Alexander has in the past been seen as a supporter of the change. He wrote to the First Minister earlier this year, saying he was 'keen' to see the introduction of what he called 'market-facing local pay.' He wrote:
But as Kirsty Williams' answers in the interview above suggest, she and her Welsh colleagues seem to have prevailed upon Mr Alexander to support their view.
Certainly she says he'll be in the front row during the debate tomorrow. Privately, others will go further and say that they're reassured that he will vote for the motion.
Perhaps this blogpost from Total Politics gives us a further clue. It claims that Danny Alexander has some making up to do with his party members.
Meanwhile a series of formal and informal meetings between Kirsty Williams and party leader Nick Clegg seem to have paid off. He told me yesterday that he's 'sceptical' about the idea of regional pay, although he stopped short of saying whether or not he'd support the motion.
Here's a reminder of what he said to me:
All this is crucial to the Welsh Lib Dems.
They see winning this motion as not only important for the thousands of public sector workers the proposals would affect, but also as important for their political future, because it would send a message to voters who believe the party has betrayed its roots and those who supported it in 2010.
And the success or otherwise of that message could make all the difference between recovery and disaster for the Liberal Democrats, not just in 2015 but also in the Welsh election a year later.