(Reuters) - France warned on Friday it would recognize a Palestinian state if a final international effort to overcome the impasse between Israelis and Palestinians failed, and proposed a two-year timeframe to end the conflict through a U.N.-backed resolution. Lawmakers will hold a symbolic parliamentary vote on Dec. 2 on whether the French government should recognize Palestine as a state, a move that the Israeli Prime Minister has called a "grave mistake". "If this final effort to reach a negotiated solution fails, then France will have to do what it takes by recognizing without delay the Palestinian state. We are ready," Foreign Minister Laurent Fabius told parliament. The parliamentary vote has raised domestic political pressure for the government to be more active on the issue. An IFOP poll showed 63 percent of French support a Palestinian state. Fabius told deputies that, were they to adopt the motion, it would not change Paris' immediate diplom...