The 2010 annual report of Enquest is available here. If you turn to page 44 (or just search for 'Conservative Party') you can find the following statement:
Political and charitable donationsThe Company made charitable, social, community-related and political donations totalling US$71,145 during the year, which includes a political donation of US$13,300 to the Conservative Party.Faced companies that make party political donations, many shareholders will oppose resolutions seeking authority to make them. But I have checked Fidelity's voting disclosure for May 2011 - which was the opportunity to vote against the company - and it voted for the resolution on Enquest's AGM agenda seeking the authority to make donations.
It should be noted that many shareholders did not feel the same way. The AGM results are no longer available on the company's website but I blogged at the time that the vote against was 30%. (For completeness, Enquest now states that it makes no party political donations, see page 17 here.)
So we have two real life examples of an asset manager that makes donations to the Conservative Party voting in favour of political donation authorities put forward by companies that made donations to the Conservative Party.
Doesn't look great does it?