Updated: 11:32 a.m.An ailing Sen. Edward Kennedy (D-Mass.) has asked Massachusetts Gov. Deval Patrick (D) and state legislative leaders to change the law governing Senate succession in an apparent attempt to ensure that his seat could be filled more quickly if he dies in the middle of his term.In a letter, a copy of which was obtained by Roll Call, Kennedy urged state leaders to amend a Massachusetts law that requires a special election for any Senate vacancy within 160 days. Kennedy who notes the succession law concerns him deeply advocates a change that would allow the governor to appoint a temporary successor until the election is held. The Boston Globe first reported on the missive.Kennedy wrote that he supports the law requiring an election, but adds, I also believe it is vital for this Commonwealth to have two voices speaking for the needs of its citizens and two votes in the Senate during the approximately five months between a vacancy and an election.To ensure a fair election process, I also urge that the Governor obtain, as a condition of appointment to the interim Senator, an explicit personal commitment not to become a candidate in the special election, he said.Kennedys letter comes amid speculation that the iconic Senator may be losing his yearlong battle against a brain tumor. Senate aides have said Kennedy appears gravely ill and has missed all but a handful of Senate votes this year while he undergoes treatment.But Kennedy spokesman Anthony Coley dismissed the notion that the letter is a sign of the Senators failing health.Senator Kennedy drafted this letter because he is thinking about the future and what best serves the interests of the state, Coley said in an e-mail. Whether its working last summer to lay the groundwork for health care reform or fighting for resources for the state for economic recovery, school repairs or infrastructure work, every day for the last 47 years the Senator has looked ahead to determine how best to serve the people of Massachusetts. This is no different.Kennedy was first elected to the Senate in a special election on Nov. 6, 1962.Though Kennedy drafted the letter last month, Coley said he delayed delivering it because he was dealing with family matters, such as the illness and death of his sister, Eunice Kennedy Shriver.When word began to leak out about the quiet conversations that have been occurring about the law, he decided he needed to get the letter into the Governor and legislative leaders hands so that his position would be publicly known, Coley said.The Globes report notes that the governor and legislative leaders have been noncommittal about changing the law, which was written in 2004 to prevent then-Republican Gov. Mitt Romney from appointing a GOP successor for fellow Massachusetts Democratic Sen. John Kerry, who was running for president.State Senate President Therese Murray and state House Speaker Robert DeLeo, who received the letter along with Patrick, are Democrats.