This week, the government faces a big electoral test in two very different constituencies: Wakefield in Yorkshire and Tiverton & Honiton in Devon.

These by-election contests may tell us a lot about the prospects of the Conservative Party at the next general election.

Might its grip on the Red Wall – the Leave-voting former Labour strongholds that delivered it victory in 2019 – be slipping? Have the Lib Dems regained their mojo as specialists in local, insurgent campaigns that mobilise discontent with government?

The by-elections may more generally tell us whether public disgruntlement over partygate and the cost of living is turning into action at the ballot box.

The Conservatives have already suffered two humiliating by-election losses to the Lib Dems in the past 12 months: first in Chesham & Amersham, where they were on the wrong end of a swing of 25 points, and then in North Shropshire, following the resignation of its MP Owen Paterson, on an even bigger swing of 34 points.

Tiverton & Honiton has a lot in common with the latter – being a mostly rural constituency, slightly older and less ethnically diverse than the national average, that voted to leave the EU in 2016 by a margin of 58 to 42.

It has been a safe Tory seat for a long time – won by the party at every election since its creation in 1997. While the Liberal Democrats typically won around 30% of the vote up until 2010, the party has not performed strongly here in elections since the coalition.

This is simply not the sort of place that the Conservative Party should be losing, even during midterm blues.

Wakefield, a former industrial town in the North of England, is a different proposition.

Held by Labour between 1931 and 2019, it is also slightly older and less ethnically diverse than the national average – but is considerably more deprived (ranking 161st on the Index for Multiple Deprivation for English constituencies).

Like many seats won by the Conservatives from Labour in 2019, it voted heavily (63 to 37) to leave the EU in the 2016 referendum. Labour are the clear challengers here.

In terms of pure electoral arithmetic, the by-elections represent very different electoral challenges. Wakefield is the 48th most marginal Conservative constituency. Labour requires a swing of just 3.8 points to win the seat.

If the government were to lose all its seats with a smaller margin to Labour at a general election, it would find itself short of a majority in parliament. Tiverton & Honiton, by contrast, is the 293rd most marginal Conservative seat.

If the Conservatives were to lose every seat the party held with a smaller majority at a general election, they would be reduced to just 72 MPs in Westminster.

A defeat in Wakefield would fire a warning shot from Labour across the bow of the government, suggesting the PM’s appeal in the Red Wall in northern England might not be as resilient as some have claimed.

A defeat in Tiverton & Honiton would be catastrophic. As well as signalling the depth of disillusionment with the PM and his party, it would further establish the trend of the Lib Dems inflicting damaging losses on the Conservative Party.

What would it mean for a general election?

If sustained at a general election, this could see the Conservatives caught in a pincer movement – having to defend against challenges from the Lib Dems in its traditional heartlands at the same time as trying to resist a resurgent Labour Party in the recently won Red Wall.

Historically, by-elections have offered a yardstick for the future electoral prospects of governments. Every government tends to lose support in by-elections, but those that repeatedly lose badly tend to fare worse at subsequent general elections.

In this parliament to date, the government has on average seen its vote share fall 7.3% in contested by-elections.

This compares somewhat favourably to many of its predecessors but is rather inflated by the party’s big win in Hartlepool in May 2021.

These latest by-elections may provide further clues as to whether the Conservatives are losing touch with the electorate, or whether they can regain the trust of voters before they next go to the ballot box.