LONDON (Reuters) - Britain s ruling Conservative Party must remain  cool-headed , business minister Greg Clark said on Thursday, after a speech by Prime Minister Theresa May at their annual conference was ruined by a prankster, letters falling off a slogan and coughing fits. The BBC reported that while ministers were rallying around the beleaguered May and praising her  guts and grace  in persisting with the hour-long speech despite the mishaps, some Conservative members of parliament were discussing amongst themselves whether to ask her to resign. Asked about such sentiment on BBC Radio 4, Clark said:  The view of the party, both parliamentary colleagues and activists, is that they regard, correctly, the responsibility of the Conservative Party to be effective and cool-headed in government.  