Health Minister Lesley Griffiths faces a double grilling from Assembly members today. This morning she'll be quizzed by members of the Health Committee. This afternoon she'll face a vote of no-confidence pushed for by all three opposition party leaders.

Those opposition parties are demanding to know how much she knew about email contact between her officials and the author of a report which was subsequently presented as independent evidence backing controversial changes in our hospital network. They say she failed to answer their questions when she made an urgent statement on this in the Assembly last week.

Lesley Griffiths has strongly rejected the claims.

Her first interrogation comes at a meeting of the Health Committee early this morning. This follows opposition demands that she be summoned to explain her position along with her officials and the report's author Professor Marcus Longley. Sources close to the minister insist that she volunteered to appear; opposition sources maintain that she only agreed after they tabled a motion to compel her.

Whatever the truth, she'll give evidence along with the senior officials in the Welsh health service and Professor Longley.

What's not clear is what effect that evidence will have on this afternoon's no-confidence vote. It's unlikely the opposition parties will withdraw it even if they get satisfactory answers from the Health Committee session. I asked each of the parties if it were even a possibility. A Plaid source told me it's not been discussed as a possibility. Welsh Liberal Democrat leader Kirsty Williams said,

It's important for both (committee session and debate) to happen to give the wider Assembly chance to scrutinise the minster on this important issue.

And the Welsh Conservatives' Assembly leader, Andrew RT Davies echoed that sentiment:

These are two distinct processes. A full debate in the chamber will allow all Assembly members to come together to scrutinise the minister. In the Health Committee (AMs with specialist expertise) can get under the skin of this issue.

There is the possibility that one of the opposition parties might change its mind based on the evidence given in the Health Committee. A Plaid source tells me the group is 'genuinely open minded about the way we vote.' Lib Dem leader Kirsty Williams says she wants to see what the minister says in the committee, but that there are 'lots of questions for her to answer.'

But even if the Conservatives, Plaid and Lib Dems remain resolute, the no-confidence motion is almost certainly doomed to fail. The Assembly is exactly split between Labour and the three opposition parties. Unless Labour fails to get all its members into the chamber for the vote (unlikely) there'll be stalemate. The Presiding Officer and Deputy Presiding Officer aren't allowed to vote but if either is required to use their casting vote, they're obliged to use it to allow further discussion (i.e they'll have to vote against the no-confidence motion.)

According to Conservative leader Andrew RT Davies, a split result will be strong enough condemnation, 'telling of the lack of credibility of the Welsh Government.'

It'll be a long and challenging day for the Health Minister. The Health Committee begins at 8.30am and the no-confidence motion is scheduled to be discussed after 5.30pm.