General election 2015: Six more key battlegrounds
You can preview the story of the coming election in London by focusing on just 13 of London's 73 constituencies.
The election is won and lost in marginal seats - those which are winnable, by the BBC's definition - through a swing of 5% in the vote.
The targets below, carrying on from my first seven, are the seats identified by parties as those that must be won to achieve their overall nationwide electoral dreams.
2010 results and key seats
8 Hampstead and Kilburn
This is the Conservatives' top London target. Labour's Glenda Jackson is exiting the stage - a decision she says is 'entirely age-driven'. She she leaves behind a majority of just 42.
The seat was a three-way marginal in 2010, with the Liberal Democrats polling under a thousand fewer than their two rivals. But will it be shared three ways for much longer?
The Labour candidate Tulip Siddiq says she can't hope to compete with her predecessor's celebrity, but she has high recognition in parts of London as the niece of the Prime Minister of Bangladesh.
The Conservative candidate Simon Marcus is a local councillor, captain of the Hampstead rugby team and the founder of a boxing academy in north London.
9 Harrow East
One might have expected to predict with some confidence the Labour reclamation of a seat lost in 2010.
If a swing of about 4% to Labour materialises across London - as suggested by one capital-focused poll in the Evening Standard in January - then this will be a Labour win.
Bob Blackman, Conservative member since 2010, is vulnerable to a swing of 3.6%. And he has just got more vulnerable. The parliamentary expenses watchdog found he had over-claimed for car travel on around 700 occasions - to the tune of about £1,000. He's challenging the decision.
Normal service, from Labour's point of view, was resumed last May when the mainstream national-party-backed group won back control at the town hall. But one of the defeated independent candidates Nana Asante is now standing under the banner of the Socialist Party, which may split off some support from Labour's candidate Uma Kumaran.
This is Labour's number one target in London and they need a swing of just 0.1% to overturn a majority of 106.
Labour has selected Andrew Dismore, MP here between 1997 and 2010, who has been keeping his hand in as a member on the London Assembly.
A major local issue is the future of the large West Hendon estate. Re-development plans have just been the subject of a planning inquiry. Residents have accused Barnet council of "social cleansing" over the plans.
The Conservative leader Richard Cornelius said it would be "a good result for the people of Barnet, particularly the people on the estate".
11 Hornsey & Wood Green
Labour have chosen Catherine West, former leader of Islington council, to contest this seat.
It should test the theory of Professor Paul Whiteley to the limit - that negativity around the Lib Dems' position may prove exaggerated, and incumbency will prove a strong counter-acting factor.
Worrying for the Lib Dems was the direction of travel suggested by the elections to Haringey council last year. Labour won 14 seats from the Lib Dems, and now hold 48 seats compared to the Lib Dems on nine.
12 Ilford North
The tendency is to see Labour's electoral hopes in terms of an arc curving westwards round from north to south, Enfield to Croydon.
But here's the seat which shows things aren't so simple. Labour are confident of taking this seat with a 5.8% swing and it certainly seems more likely at the moment than success in Battersea and Finchley & Golders Green which are also Labour targets.
This is typical commuter belt, and although it is within the M25, demographically the constituency resembles the Essex commuter towns which lie to its north-east.
13 Sutton and Cheam
There are consolations when you lose a job.
Removed from his post as health minister in 2012, Liberal Democrat Paul Burstow was able to be unconstrained in his condemnation of plans to close the maternity and A&E units at the local hospital St Helier. It may help him in a tight tussle with the Tories who need a swing of 1.7% to overturn his 1,608 majority.
There will almost certainly be a strong incumbency factor helping Burstow. A sense of acceptance of the Lib Dem way has become reinforced in this part of south west, suburban London where the local council has been run by the party for 28 years.
They won 43 of the 54 seats in last year's borough elections, gaining 11 from the Conservatives and defeating the Tory group leader Paul Scully, who is the party's candidate against Burstow in Sutton & Cheam.
And worth watching...
What we have here is a potentially fascinating three-way marginal.
According to a recent report, it's to Thurrock that many Londoners, looking for somewhere near to settle, are choosing to relocate.
For only the second time since the war, the Conservatives won the seat in 2010 by just 92 votes.
Former BBC journalist and special adviser Polly Billington is seeking to take it back from Jackie Doyle-Price. The complicating factor is UKIP.