Is an early Holyrood election actually in the interests of any of the opposition parties?

I don't take seriously all the chatter about the Budget failing and an early Holyrood election being called, because past history shows that a resolution is generally found - even if it happens very theatrically at the last minute.  However, the best way to judge the true level of danger in these situations is to ignore what opposition parties are saying in public and consider whether in the case of each party an early election actually serves their own self-interest.

Labour:  Even for Labour it's not a straightforward equation.  They would undoubtedly gain a large number of seats in any early election, but it's unlikely to be the clear-cut victory they were starting to take for granted only a few months ago, so there's a danger of looking like a firework that fizzled. That might drain momentum away from them as they look ahead to the 2026 election, which under the rules would still take place.  On the other hand, they might get into government, which is the ultimate goal for any party, but that would almost certainly require a deal with the Tories and possibly with Reform UK as well.  That would be bound to complicate their 2026 campaign, ie. "a vote for Labour is a vote for the Tories and Farage".

Conservatives: Without question an early election is not in the Tories' best interests.  They would lose up to half their seats, would drop to third place or possibly fourth, and would see Reform UK open up a bridgehead against them.  The chance of having some power or influence within a new unionist government surely doesn't outweigh all of those negatives.  So in a rational world, if there looked to be any danger of the SNP government falling, they would head off the danger by abstaining somewhere along the line.  In practice it's very difficult for them to do that, though, because it would damage their anti-SNP-ultra tough guy image.

Liberal Democrats: On paper an early election is very clearly in the Lib Dems' interests, because they would stand to gain seats, and would have at least a chance of a share in power.  So it's interesting that they seem to at least be theoretically open to a deal (remember they also saved the SNP's bacon when other parties tried to prevent Kate Forbes from becoming Deputy First Minister).  Maybe party finances are the explanation - it could be the Lib Dems have limited resources and would prefer to save them for one big push in 2026.

Greens: It's not simple for the Greens, because polls often suggest they would see some progress in an early election, but that progress wouldn't be dramatic, and they have to weigh that against the fact that they currently hold the balance of power, and might hand that privileged position to Reform UK on a plate if they bring down the SNP government.  For that reason, my guess is that an SNP-Green deal will rescue the Budget, with the second most likely escape route being an SNP-Lib Dem deal (even though the latter doesn't make intuitive sense).