One of the most important rules of political betting (or indeed of any kind) is that you need to acknowledge what is likely to happen rather than betting simply on what you’d like to happen. So most of my tips for the general election are based on the probability of a Conservative landslide.
Firstly, I’m going to suggest that you take advantage of 888.com’s 1/7 (87.5%) on the Conservatives getting an overall majority. The Tory landslide implies that Labour will do badly in terms of seats. While my gut tells me that they’ll get more than 150, there’s a good enough possibility that they could poll under this figure. So I’d advise taking 6/4 on them getting 150-200 and 7/4 on them getting 100-150, both with Ladbrokes. This gives combined odds of 76.4%. If you properly weight this bet in line with the odds, this should work out to £5.24 on 150-199 and £4.76 on 100-149 for a hypothetical £10 unit.
In terms of vote share I’d predict that Labour will get less than 30%, but more than 20%. I’d therefore go with Ladbrokes’ 9/4 on 25-30 and 6/4 on 20-35. This works out to combined odds of 71%. Again, the proper weighting for a £10 unit would be £5.65 on 20-25 and £4.35 on 25-30. I’d also definitely take the 1/8 (89%) with Ladbrokes on Labour getting more votes than the Lib Dems.
As far as the Lib Dems are concerned, I predict they will get at least ten but no more than 39 seats, simply because a surprising number of their targets are in areas that voted Leave. As a result, you should go with 5/2 on 10-20, 5/2 on 20-30 and 5/1 on 30-39, all with Ladbrokes for combined odds of 74%. This works out at £3.87 on 10-19, £3.87 on 20-29 and £2.26 on 30-39. I also suggest you make a separate wager on them getting between 10%-20% of the vote at 2/5 (71%) with Ladbrokes.
I think the 2/7 (78%) on Ukip getting no seats with William Hill is a steal. Finally, while Corbyn will leave the Labour leadership this year, I think he will stay on for a short period to ensure that he can control the terms of any future leadership contest. So I’m tipping him still to be Labour leader on 9 July at 5/4 (44%) with William Hill.