The 2018 local elections are the first in a sequence of local elections in which the Liberal Democrats have the opportunity to start to repair some of the damage they suffered to their councillor base while they were in government.

When these councils were last contested in 2014, the Liberal Democrats lost 310 councillors and lost control of two councils: Kingston-upon-Thames in London and Portsmouth on the south coast. But they held onto the Watford mayoralty, thanks in part to the local popularity of the incumbent Dorothy Thornhill.

So in many ways the obvious answer to what makes a “good night” would be for the Liberal Democrats to gain, say, 100 or so councillors and to retake one of their lost councils. (For the purpose of this series, I am ignoring the polls and I am not making predictions. I am simply laying out what success or failure actually looks like. I will make a set of predictions and observations nearer the close of the local election campaign.)

But this obvious answer would, in my view, be dead wrong. One of the correct calls that Tim Farron made was to recognize that the party had no practical way to return to being the anti-system party it became under Charles Kennedy: coalition didn’t just damage the party electorally, it permanently altered who it could appeal to. Back then, it did an excellent job of harvesting votes to the left of the Labour party and emerging as the only viable anti-Conservative party across much of the south coast and south west London.

The party is simply not going to regain many of the seats it held as a result of being “not the Tories” or “none of the above” before going into coalition, so in many ways the 2014 losses and holds are entirely irrelevant to deciding what would constitute a good night for the party.

Rightly or wrongly, Farron decided that the Liberal Democrats’ new identity was a party of the 25 per cent of people who want the referendum to be re-run or merely halted, and that decision helped boost the party’s membership thanks to an influx of committed pro-Europeans. The party’s ultra-democratic structures means it’s likely that the Liberal Democrats will remain a firmly committed anti-Brexit party, so a “good night” has to be seen through the prism of whether or not they are successfully leveraging that stance into votes and whether that stance is actively repulsing those voters who remained loyal throughout the coalition years.

On a good night the party would retake Kingston-upon-Thames and Richmond councils. Winning the latter would be a particular boon as it would show that their revival in the Richmond Park constituency is not merely a result of Zac Goldsmith’s post-2016 unpopularity locally.

They would retain their remaining presence in Labour fiefdoms like Manchester, Leeds, Hackney and so forth, and while they might not make gains they should at least gain votes in strongly Remain areas, particularly in places where there are large numbers of European citizens – who cannot vote in general elections but can vote in the local elections. They ought to break into double figures on Oxford City Council, and on a good night they would deprive Labour of their majority on Cambridge Council.

However, should the Liberal Democrats hold onto the Watford mayoralty, that would not just be a good night but an exceptional result: the party tends to struggle when it loses an incumbent, and Dorothy Thornhill is stepping down. In the party’s favour, they are very strong at a local level there – they won 25 seats out of 36 in the 2016 local elections – so that may count in their favour. However, given their disastrous 2017 general election result, holding onto the Watford mayoralty would be a great sign. It would indicate that some of the squeeze of their vote in 2017 was a tactical “stop the Tories” vote rather than a prolonged and permanent shift, and that they can still win in Watford when Thornhill is not at the top of the ticket.

But they shouldn’t worry overmuch if the price of the above turns out to be falling away further in the likes of Solihull or Portsmouth, as that may be the price they pay for developing a more coherent and durable base of support for battles to come.

Thi is one of a series on the coming local elections in England. You can read about Labour’s prospects here.