Conservative lawmaker Zac Goldsmith, a vocal opponent of the expansion of Heathrow Airport, yesterday notified the government of his decision to resign from parliament, the finance ministry said in a statement. Goldsmith, who represents a constituency near the airport, had previously pledged to quit if Heathrow was given the go ahead to expand — something which happened earlier yesterday. The resignation will prompt an election for his west London seat. Goldsmith, who unsuccessfully ran for London mayor earlier this year, is expected to run as an independent candidate.  Goldsmith’s resignation will be more a headache for the prime minister as the Conservatives will have to decide whether to put up a candidate against him in a seat previously held by the LibDems, who oppose Heathrow expansion.