Ashcroft is deputy chair of the Conservative Party and the party's largest donor, funding the active constituency campaigns of many candidates in marginal seats and having a significant voice in campaign strategy.
Tim Montgomerie of ConservativeHome, which has established itself as the leading grassroots forum, blogged about the deal under which Lord Ashcroft now has a 57.5% per cent stake in the site. Montgomerie tells readers that is confident in the assurances of editorial independence which he has received from Lord Ashcroft, that he will not seek to influence the editorial content of the ConservativeHome website.
Intriguingly, the investment (which I have not seen quantified) is to create a new centre-right online "newspaper".
This is Andrew Rawnsley's statement about PoliticsHome.
I have today resigned as Editor-in-Chief of PoliticsHome.co.uk.
Thanks to the dedication and flair of the team, PoliticsHome has been an outstanding editorial success. The site has attracted plaudits from many other media organisations and across the political spectrum.
That praise has been generated by its ground-breaking methods of surveying opinion at Westminster, Whitehall and beyond along with its impartial reporting of all strands of news and commentary.
It has been both professionally and personally satisfying to work with the talented people who have achieved this in the eighteen months since the inauguration of PoliticsHome.
I therefore greatly regret the decision made by Stephan Shakespeare, the chairman, to do a deal which places PoliticsHome under the ownership of Michael Ashcroft, the deputy chairman of the Conservative Party. The site has been folded along with ConservativeHome into a new entity in which Lord Ashcroft is the majority shareholder.
I became Editor-in-Chief on the basis that PoliticsHome was dedicated to being a non-partisan site clearly independent of any party both editorially and financially.
It was essential for users of the site that they could feel absolute confidence in the political independence of PoliticsHome.
I do not believe that can be compatible with being under the ownership of the deputy chairman of the Conservative Party.
Update: PoliticsHome have issued their own statement, which does not refer to Andrew Rawnsley's resignation.
I am asking PoliticsHome whether the amount invested by Lord Ashcroft will be made public. I am also putting the same question to Tim Montgomerie of ConservativeHome. This seems to me to be one small step in the direction of transparency. I will report back on any response.