As I wrote earlier this week, even if everything in Labour’s garden were rosy, the 2017 local elections map is very testing for them. But for Britain’s other opposition party, the Liberal Democrats, the map is much better.

For a start, the Liberal Democrats come into these elections having lost 1,924 seats overall in the coalition years. The only way is up, to be frank. (Though to put the argument that Labour has reached “peak gain” in perspective – that party had equalled the Liberal Democrats’ coalition-era losses by the 2000 locals. When Ed Miliband left post as Labour leader, he had gained just 1768 council seats overall, so Labour has considerable potential for growth even to be back at its local government strength at the peak of Tony Blair’s unpopularity in 2006. But that’s a topic for another time.)

It’s not the most appetising map you could imagine for the Liberal Democrats; that will come in 2019, when seats last contested in the nightmare years of 2011 and 2015, when they lost 750 and 488 seats respectively, will come up for election. My expectation is that far as seat gains are concerned, the Liberal Democrats will “win” the 2019 local elections.

Still, the Liberal Democrats lost 124 seats when these seats were last up, which should give you an idea of what a “good night” for them is. If they can make some or all of that back, that will add to the feeling that their opinion poll showing is underestimating their electoral standing. (My hunch, for all that it’s worth, is that the polls are underestimating the Liberal Democrats, as they tend to do with the minor parties between elections.)

So the 100 seat gain predicted by the academics Colin Rallings and Michael Thrasher, and the 125 seat gain predicted by Robert Hayward, a pollster, would add credence to the idea that the “Lib Dem fightback” is considerably more than hashtag. Anything beyond that would be a great night. Anything below 80 would be a disappointing night.

That’s the numbers, what about the locations? The biggest prize for the Liberal Democrats is the West of England, where Stephen Williams, the MP for Bristol West from 2005 to 2015, is their candidate for the new mayoralty. This is the only three-way marginal of the new mayoralties, and if the Liberal Democrats win here, they will be well-placed for recovery in the region come 2020. (Equally importantly, a Liberal politician will be in office and in power alone for the first time since 1915.)

In Scotland, where unlike England their 2016 performance was of stagnation rather than revival – they did better in the constituency results but were duly punished in the lists, ending the day with the same number of seats as they started – they will hope to perform well in Edinburgh and East Dunbartonshire - the two areas they have the best hope of winning back in 2020.

In Wales, they should hope to gain in Cardiff and Ceredigion. In Powys, which contains two seats where they might hope for a revival in 2020 the picture is more complicated as the council is governed by a coalition of independents.

In the six unitary authorities up for grabs in England, they have serious prospects for gains in all of them. A good night would see them become the official opposition in five and they have a decent hope of being the largest party in the Isle of Wight. In Cornwall, where they are the largest party, they should win a majority on the council.

In Doncaster, they are defending nothing at all. On a very good night, they would pick up three councillors.

The other big prizes for them are the county councils: Cambridgeshire, Devon, Gloucestershire, Norfolk, Oxfordshire and Somerset are the particularly promising areas. Look, too, to the seats they lost in 2015. Gains, both in council seats there and in the popular vote, are the real gold dust.