L seems to me to be the best option for the following broad reasons:

 1.   The placing of pressure on parties by corporations (and this includes the trade union movement as well as employer interests) is undesirable.  It is therefore a good idea to restrict donations to individuals and, crucially, to cap them at a level affordable to 'Joe and Jo Public'.  This may mean considerable reductions in funding in the initial stages of such a law coming into effect, but such a scanario will force parties to (gasp!) engage with their constituents.  if they want support, they cannot expect to get it without some effort.  High-flown, big money, glitzy media campaigns are unnecessary in any case.  Local activism is the way forward.

2.    Placing tighter fiscal controls on party activities during elections sounds good in principle.  The precise nature of these controls would have to be carefully thought out, of course, but should aim to be fair to the less well represented parties.

I suppose parties could earn income from other sources and devote it to electioneering. (In reality, they do do this either incidentally to other activities or as "fundraising" explicitly, but the boundaries between such income and donations are or may be unclear.)

Would a national chain of Conservative Party second-hand shops, etc. with profits committed to the political arm be problematic?

If there was State funding, what about endowment rather than income funding, perhaps, with periodic adjustments, and new parties allowed to receive other funding until endowed or if disendowed (having become politically too marginal to qualify)? (Established, unestablished, disestablished parties.)

I'm not in favour of any of this, just adding to the chaos of possibilites. 

I do think that the issue of "corruption" or still more broadly impropriety in decision-making is absolutely crucial here, and what the funding issue is rather an indirect attempt to get at. So, what decisions should be taken on the basis of party political or personal political advantage (including funding considerations), what may be or have such considerations contributing, and what should not? There seems a broad spectrum from the quasi-judicial to the "purely political". It's not at all obvious that the major problems with impropriety are to do with funding, when you look at the many years of trying to look tough in the Home Office for a transient good press or purely political positioning (the extension of control orders now), or all the anxieties about Murdoch among both main parties, with so many dreadful consequences for real people.

Banning state funding removes the opportunity to apply it constructively, as suggested in options C and E.   

Are we allowed to modify the rule set?  Avtar Singh says L is the only option yet at bullet 2 L permits individual donations (Mr Hinja) while Avtar excludes them in his line 2.  Membership fees are never likely to generate much income from ordinary voters.  Why should they be inclined to pay when they can vote anyway (or not vote as the case may be)?  Our first problem is to regenerate an interest in politics and, though having candidates knock on doors may go some way to that I doubt many punters will put a pound or two in their out-held hats.

...and to treat David A's concerns about Plaid Cymru ... if he was allowed to nominate the candidate who was to receive his entire tax deducted electioneering contribution then Plaid Cymru would get his contribution and no one else/no other party  would benefit (which is surely how it should be).  Conversely MY entire contribution might be nominated to some other party or, for preference, individual aspirant candidate. 

Properly managed, State funding places financing parties/candiadtes of all hues in the hands of those who wish to support/promote them but, unlike corporate and individual donations, does so on an equal footing for all so reducing the 'buying influence' risk . 

I agree that funding for aspirants for other than parliamentary elections needs further thought. I support the need to enable 'independents' to have an equal opportunity againts the big boys.   

Avtar Singhs version of L, allowing membership fees only, seems to be aiming at equal opportunities to stand for election and put forward an agenda, and I think it would achieve this to some extent. Restricting funding to membership fees - assuming those are fixed and equal - would prevent some of the undue influence exerted by corporations and individuals. It would nevertheless benefit large, established parties and inhibit the growth of new ones. A limit on expenditure would offset that, though I dont immediately see why it should be fixed at the level of the LIbDems. Also, Im not convinced we need to prevent the emergence of the small and daft;. Most things are small when they are born, and many good ideas have been thought daft at their origin.

Quantitatively, the larger the party the more members it would have and the more finance available for it capitalise on an established vote share. As the number of members of a political party do not reflect society at large and the party-population share it is impossible and incrementally false to believe that a system of membership-for-finance alone would be representative or even equal. How could ten members, with say 10000 votes each, even stand a chance against the machinery of the efficient, well oiled national parties that could combine their lot in a pool of central planning and resources. Would the Election Commission have to play the big brother and provide vast support through access to political calibrators such as tax breaks on campaign resources?

Qualitatively, I think in a democracy we would need to spread the sources of poltical capital around so as not to beg for corruption by streamlining funding at one point. What are the incentives for politicians do get votes, other than to spend your membership fee and get into parliament, when there are other interests and groups in society that need to be a part of this process too? I am not suggesting to regulate it off the map, but all members of society need to be a part of the process, and they too need incentives to be a part of politics. Giving membership fees and casting a vote behind it is not deliberative democracy -it is more akin to peer pressure.I neither agree with K, L or M.