By Lawrence Hurley and Andrew Chung

WASHINGTON, Sept 21 (Reuters) - President Donald Trump on Monday prepared to push ahead with plans for his third U.S. Supreme Court nomination, which would cement a 6-3 conservative majority, as some Republicans wavered on whether to support the move weeks ahead of an election.

The death of liberal icon Justice Ruth Bader Ginsburg upended the campaign season, giving Trump and his party an opportunity to strengthen its grip on the court whose decisions influence most spheres of American life, from healthcare to gun rights to voting access.

Trump and top Republicans including Senate Majority Leader Mitch McConnell also gained a chance to steer the national discussion away from the coronavirus pandemic, which has killed almost 200,000 Americans and thrown millions out of work.

Democrats accused McConnell of hypocrisy for being eager to usher a Trump nominee to a confirmation vote. In February 2016, he refused to hold a vote for a nominee of Democratic President Barack Obama following the death of conservative Antonin Scalia, saying it would be inappropriate in an election year.

At least two Republican Senators -- Maine's Susan Collins and Alaska's Lisa Murkowski -- said over the weekend that the Senate should not vote on a nominee so close to an election, the first dissent against the idea from McConnell's 53-47 majority.

Trump said in an interview with Fox News on Monday that he wanted to wait until Friday or Saturday to announce his nominee out of respect for Ginsburg.

"We should wait until the services are over for Justice Ginsburg," he said.

Trump said a vote on his Supreme Court nominee should come before the Nov. 3 election.

"We won the election and we have the right to do so we have plenty of time, a lot of time," Trump told Fox. "The final vote should be taken frankly before the election. We have plenty of time for that."

Trump's rival in the Nov. 3 contest, Democratic former Vice President Joe Biden, called on other Republican senators to join them, and allow the winner of the election to name the next Supreme Court justice.

A Reuters/Ipsos poll published on Sunday found that a majority of Americans -- some 62% including about half of Republicans polled -- agreed with that sentiment.

Trump said on Saturday that he would this week select a female jurist to fill Ginsburg's seat, and named two possible candidates: Amy Coney Barrett of the Chicago-based 7th Circuit and Barbara Lagoa of the Atlanta-based 11th Circuit.

"We were put in this position of power and importance to make decisions for the people who so proudly elected us, the most important of which has long been considered to be the selection of United States Supreme Court Justices. We have this obligation, without delay!" Trump said on Twitter on Saturday, repeating the message Sunday.