There’s been a lot of heat and light generated over the last few hours over the contenders’ appearances today on The Politics Show and The World This Weekend - and it does indeed seem to have been less than our party’s finest hour. (Though in the midst of it I have been enjoying the grounding effect that the aggregator, Lib Dem Blogs, brings to it all, so that furious posts like Huhne - now he has really cooked his goose are also interspersed with ones of much more local interest with titles like Lib Dem appointed Camden Cycling Champion!).

But even leaving aside that little spat it’s been increasingly clear to me over the last few days that momentum is again increasingly behind the Clegg campaign. Now of course most readers will scarcely be surprised to hear that that’s my view, given I have been backing him from the start. But I hope you’ll hear me out before deciding whether to dismiss my view on those grounds.

Nick started this campaign as the frontrunner (declared by the media, as nobody has much of a clue what actual party members think). The normal way this works is that after an initial burst declaring the frontrunner to be the frontrunner, a challenger then has the momentum with them, as everyone gets (depending on your interpretation) either bored or resentful with the idea of the frontrunner staying in front all through the campaign. (This was indeed why the Clegg campaign looked so worried by him being labelled in this way and at the start put in strenuous efforts to downplay it!). And there has certainly been some of this - Chris’s campaign has had some good moments, and in particular, as I’ve noted on this blog, he has communicated his ideas in a more animated way than he often has in the past.

But a month into the campaign, and a few days before many members will actually cast their vote, the momentum again seems to be with Nick.

What’s my evidence?

Well, Nick started the weekend with an unambiguous endorsement from the Guardian newspaper, who said this leadership contest is an important choice, and the party should choose Nick. Now, we all know that Lib Dems became Lib Dems because they don’t like to be told what to do or think - but nevertheless the endorsement of the Guardian is important (and the Guardian doing it is also a far cry from one of the right-wing papers doing so - although the Telegraph did also run a story about how a Clegg leadership could well put an end to the Cameron bandwagon, just for good measure!).

Since then three more MPs have come out for Nick, representing a spread of the now fairly small number of undecideds: Jo Swinson, our youngest MP (and someone who I know from talking to her was previously completely undecided), Alan Beith (whom I might offend if I call him our oldest MP, but is certainly one of our most longstanding and respected and cerebral MPs), and Dan Rogerson from the other end of the country in Cornwall and like both Nick and Chris one of the 2005 intake. The Huhne campaign have this weekend unveiled Evan Harris MP as backing Chris; as we know, most Lib Dem MPs had already declared for Nick.

Then there was the news that 21 Lib Dem members of the House of Lords were backing Nick. These are informed people who know both candidates well, but who are not so dependent as MPs are on the goodwill of the future leader, so have no real reason other than their own independent judgement to come out for a particular candidate. The Huhne campaign have announced that Lord Dholakia is backing him.

I understand also that Nick’s campaign are also claiming that he has a larger number of councillors and especially Lib Dem leaders of councils (Lib Dems actually exercising real power) backing him, though I don’t know the details of this.

Then we have the fact that Nick last week won the Spectator award for Newcomer of the Year. This is a cross-party set of awards and other people to win awards in this grouping were the current First Minister of Scotland, the First Minister of Northern Ireland, two former Prime Ministers and two other former party leaders. Although I obviously don’t agree with the politics of those from other parties, I would like our party to elect a leader who fits in to this kind of bracket too!

And then there are some of the raw numbers: notably the survey of Lib Dem constituency chairs in held and marginal seats for the World this Weekend which came out at Clegg 43 and Huhne 30, and the fact that Clegg has had 1500+ party members tell his campaign that they are supporting him, to Huhne’s 1000 (Update Sunday evening: the Huhne website now says the “full declared supporter list to date” is now “over 1100″). Personally I find it difficult to attach much weight to these raw numbers in an electorate of 65,000-odd, but they do seem to imply that while Nick is not currently in a landslide position, he does have a significant lead.

So for all these reasons I think momentum is with Clegg again at the moment - which as I say is all the more surprising because at this stage it’s often “supposed” to be with the challenger.

Not everyone agrees with this assessment - the Huhne campaign don’t (rather unsurprisingly!) and more impartially the Observer today takes a different view to me. However their interpretation seems to be based on non-attributable assertions by unnamed people, rather than any actual facts, which makes their article read a bit more like an attempt by the journalist to try and find a story to file on this selection, rather than any actual information!

And on top of all this I do think that today’s incident with the attack briefing on Clegg will turn out to make quite a difference, sealing Chris’ reputation as the “nasty” candidate in this contest. We first saw this with his attacks that Nick is some sort of analogue of Cameron. We then went on to a series of repeated claims that Nick was proposing a policy that he made very clear he wasn’t, and then there was the Chris Clarke incident, in which the Huhne campaign posted up on their official website an attack on Nick which was so controversial that it had to be withdrawn. (We should not, by the way, attach any credibility at all to the reason given for that mistake that it was all down to the naivety of Anna Werrin, one of Chris’s campaign staff. For anyone who doesn’t known, Anna was the key fixer behind Charles Kennedy’s leadership of the party for six years and the idea that she is “naïve” about these things is one of this campaign’s less realistic claims!).

However despite the consistent thread of these incidents, most of them, while noted by those following the campaign closely, did not have a high profile and will not have been noticed by most party members.

But today’s attack briefing on TV is different: not only was the Politics Show one of the key informers for many armchair party members, but in addition the media, somewhat bored by the contest so far, have clearly decided that this is a good juicy row that they can latch on to, and I am sure this serious mistake by the Huhne campaign will be featuring prominently in the newspapers tomorrow and in discussion of the contest over the next crucial days.

The momentum was again with Nick even before today’s events. Following this further - and really pretty serious - error of judgement by the Huhne campaign, it is now more than ever.