Ceri Fowler (University of Manchester) and Chris Butler (University of Manchester)

The defection of 8 Labour and 3 Conservative MPs to form “The Independent Group” (TIG) in February 2019 set Westminster alight with intrigue about what impact they might have on UK politics. With both major parties struggling to find a position on Brexit which unites their Parliamentary Party and voters, there has been much speculation about whether The Independent Group could become a viable electoral force, and whether they are more likely to take votes from one party rather than the other.

Whilst the MPs involved have been keen to dismiss the notion that they are an SDP Mark II, many commentators have predicted that the 11 TIG MPs face an uphill battle to hold onto their seats, similar to how only 4 of the 29 MPs who defected to the SDP were re-elected at the subsequent general election.

The SDP/ Liberal Alliance polled 25.4% of the vote in 1983, just short of Labour’s 27.6%. Yet they only won 23 seats compared to Labour’s 208 as their vote was spread so thinly across the UK. However, TIG could fare better if their supported was more concentrated in particular constituencies. To understand how TIG might fare under the UK’s first past the post system, we looked at the available polling data on TIG support.

Our key findings:

· There is very little prospect of TIG gaining any new seats or of most of the current MPs holding on.

· If allied with Liberal Democrats, TIG could come close to denying the Conservatives a majority, particularly if Conservative MPs such as Justine Greening also made the jump.

Where might TIG fare best?

To calculate how TIG might fare under first past the post, we looked at data from the 2011 census on constituency demographics to give each constituency a TIG rating. Polling has shown (ComRes, Deltapoll, Survation, YouGov) that voters are more likely to support TIG if they:

· Voted remain

· Are educated to at least degree level

· Aged between 35 and 54 (although this varies slightly as different pollsters use different age intervals)

· Are classed as ABC1

We also included a weighting for the proportion of Jewish voters in a constituency to take into account that Jewish voters are likely to share many values with the Labour party but seem to be put off by the party’s anti-semitism rows and may consider TIG as an attractive alternative (see work by our colleague Andrew Barclay).

We generously took TIG’s high point in the polls of 18% and distributed it across constituencies according to their TIG rating. We then adjusted the other parties’ vote shares according to TIG supporters’ past voting intentions .For simplicity’s sake, vote swings between other parties were applied uniformly, rather than also being based on demographics.

TIG’s best prospects are listed in the table below. Even with taking their most generous poll rating so far and weighting it by favourable demographics, our model does not predict that TIG win any seats.