In the space of under a month, the odds on a hung parliament after the election have moved from Evens to 4/7.

The main development behind this has been the startling polling coming out of Scotland showing the possibility of sweeping SNP gains, mainly at Labour’s expense. The continued good showing of the Greens at the polls has also hurt Labour disproportionately.

Meanwhile, UKIP’s numbers have shown no sign of declining and the prospect of a comfortable win for Mark Reckless in Rochester next week isn’t going to help the Tories – UKIP are now 1/33 to win the by-election.

Is the betting shift reflected in the political scientists’ forecasting models? I’ve taken the latest estimates from a couple of excellent sites; Steven Fisher at electionsetc and Chris Hanretty at ElectionForecast and compared them to the probabilities suggested by Ladbrokes’ latest odds

ResultLADBROKESFISHERHANRETTYAverage
NOM59%56%79%65%
Lab Maj23%19%9%17%
Con Maj17%25%12%18%

The Hanretty estimate of a hung parliament would make it just under a 1/4 chance, which makes our 4/7 offer look quite generous. Both models make a Tory majority more likely than a Labour one, although that isn’t reflected in the betting yet.

All of this makes the market on what the post-election government will emerge even more open. We’ve seen a bit of money in recent days for a Lab/LD/SNP coalition, which has shortened up from 33/1 to 20/1.

Oh dear. The Ashcroft Scottish constituency polling may have been very bad news for Jim Murphy, but it wasn’t much better for Ladbrokes. We were hoping it might show some encouragement for Labour in some of their safest seats, but no. We are now sitting on some hefty losses if the SNP do as well as this polling suggests.

The SNP are now clear favourites in 40 seats in Scotland. Below is a list of every constituency, with their odds. You can find all of our latest constituency betting here.

Seat2010  WinnerSNP Odds
MoraySNP1/100
Dundee EastSNP1/100
AngusSNP1/100
Banff and BuchanSNP1/100
Perth and Perthshire NorthSNP1/33
Na h-Eileanan an IarSNP1/25
Inverness, Nairn, B & SLib-Dem1/8SNP GAIN
Argyll and ButeLib-Dem1/10SNP GAIN
Dundee WestLabour1/7SNP GAIN
GordonLib-Dem1/7SNP GAIN
Ochil and Perthshire SouthLabour1/6SNP GAIN
FalkirkLabour1/5SNP GAIN
Caithness, Sutherland & ERLib-Dem1/5SNP GAIN
Glasgow EastLabour1/3SNP GAIN
Ayrshire North and ArranLabour1/3SNP GAIN
Fife North EastLib-Dem1/3SNP GAIN
Cumbernauld, Kilsyth & K.E. Labour1/5SNP GAIN
Glasgow NorthLabour2/5SNP GAIN
Kilmarnock and LoudounLabour2/5SNP GAIN
Linlithgow and Falkirk EastLabour2/5SNP GAIN
Motherwell and WishawLabour2/5SNP GAIN
Glasgow SouthLabour2/5SNP GAIN
Aberdeen NorthLabour4/9SNP GAIN
Dunbartonshire WestLabour1/2SNP GAIN
LivingstonLabour1/2SNP GAIN
Glasgow CentralLabour1/2SNP GAIN
Edinburgh EastLabour1/2SNP GAIN
InverclydeLabour4/7SNP GAIN
Paisley and Renfrewshire SLabour4/7SNP GAIN
Airdrie and ShottsLabour4/6SNP GAIN
East Kilbride, Strathaven & LLabour4/6SNP GAIN
Glasgow North WestLabour4/6SNP GAIN
Lanark and Hamilton EastLabour4/6SNP GAIN
MidlothianLabour4/6SNP GAIN
Paisley and Renfrewshire NLabour4/6SNP GAIN
StirlingLabour4/6SNP GAIN
Dunbartonshire EastLib-Dem4/6SNP GAIN
Edinburgh WestLib-Dem4/6SNP GAIN
Aberdeen SouthLabour8/11SNP GAIN
Aberdeenshire W & KincardineLib-Dem4/5SNP GAIN
Glasgow South WestLabourEvs
Coatbridge, Chryston & Bells’Labour11/10
Ayr, Carrick and CumnockLabour5/4
Ayrshire CentralLabour5/4
Dunfermline and Fife WestLabour6/4
Ross, Skye and LochaberLib-Dem6/4
Edinburgh South WestLabour13/8
Edinburgh SouthLabour7/4
GlenrothesLabour15/8
Edinburgh North and LeithLabour15/8
Glasgow North EastLabour2/1
East LothianLabour2/1
Renfrewshire EastLabour9/4
Kirkcaldy and CowdenbeathLabour11/4
Rutherglen and Hamilton WestLabour11/4
Dumfriesshire, Clydesdale & TConservative3/1
Dumfries and GallowayLabour3/1
Berwickshire, Roxburgh & SLib-Dem3/1
Orkney and ShetlandLib-Dem4/1

Ladbrokes took a £16,500 bet on UKIP at 1/33 to win the Rochester by-election today. That intrepid punter will be collecting a £500 profit on Friday morning if things go as expected. If by some chance the Tories pull off a shock victory, it will probably be the most profitable by-election result in history for the bookies. I don’t hold out much hope.

The media narrative has already moved on to the guessing game of whether any other Tory MPs will be jumping ship. We now make it odds-on that at least one other Conservative defects before Christmas.

Favourite for a while now has been the MP for Kettering, Philip Hollobone. Interestingly, he is an old boy of Dulwich College, along with Nigel Farage. Some shrewdies have been backing UKIP to win his seat at the general election, now 6/1. I guess that might be better value than the 2/1 about him being next out.

The morning after last week’s Rochester and Strood by-election, we made the Tories 4/6 favourites to re-take the seat next May. Punters have been even more bullish and the Conservatives are now even stronger favourites, at 1/2, with UKIP drifting out to 6/4

According to our individual constituency prices, that means Rochester & Strood is now the eighth most likely win for UKIP at the general election. The UKIP win % is the chance of them taking the seat at the general election, as implied by our odds.

RankSeatWin 2010UKIP Win %
1ClactonCons82.25%
2Thanet SouthCons64.58%
3ThurrockCons57.47%
4Boston & SkegnessCons56.06%
5Great YarmouthCons40.33%
6Castle PointCons38.47%
7Thanet NorthCons36.55%
8Rochester & StroodCons35.87%
9Great GrimsbyLab32.94%
10RotherhamLab28.51%
11Cannock ChaseCons27.91%
12DoverCons27.77%
13Louth & HorncastleCons26.29%
14Basildon S & Thurrock ECons25.67%
15Folkestone & HytheCons22.65%
16Sittingbourne & SheppeyCons22.57%
17EastleighLD20.81%
18Camborne & RedruthCons20.23%
19St Austell & NewquayLD19.83%
20Portsmouth SouthLD19.66%

So, 15 of their top 20 prospects are Tory held seats although it’s worth pointing out that UKIP might prevent Labour from winning seats like Thurrock, Yarmouth and Cannock Chase which would all be very high on Ed Miliband’s target list.

As the betting markets continued to reflect the SNP’s rise in the polls, a new milestone was established this week when they became favourites to win a seat in Glasgow this May. The nationalists are also breathing down Labour’s necks in the other six, according to Ladbrokes’ latest seat-by-seat odds.

2010 Lab vote %2010 SNP Vote %Lab OddsSNP Odds
Glasgow North44.511.911/104/6
Glasgow Central52.017.54/611/10
Glasgow East61.624.78/1511/8
Glasgow South51.720.28/1511/8
Glasgow North East68.414.11/39/4
Glasgow North West54.115.32/75/2
Glasgow South West62.516.32/75/2

Glasgow North, a constituency in which they got under 12% of the vote in 2010, now has the SNP as favourites. In the days before the Independence referendum, you could have backed the SNP at 10/1. It’s tricky for those of us who attempt to predict elections to simply ignore the results of the last election; perhaps we all have to accept that the Scottish political landscape has changed for ever and that anchoring our expectations to 2010 is pointless.

Interestingly, this seat saw a huge gamble on the Liberal Democrats to take it at the last general election – they went off at 5/4 on the day. You can have 100/1 for them to win it this year.

Glasgow East was an SNP by-election gain in 2008, only for Labour to win it back easily at the general election, so there is some history of nationalist success in the city. If they are going to do as well in May as current polls suggest, they will almost certainly end up winning seats like this. Perhaps the 11/8 is still a value bet.

Page 1 of 212