WASHINGTON — Linking two of the politically volatile issues of the moment, Senate Democrats say they will move forward this week with a plan that would eliminate tax breaks for big oil companies and divert the savings to offset the deficit.

With high gas prices and rising federal deficits in the political spotlight, senior Democrats believe that tying the two together will put pressure on Senate Republicans to support the measure or face a difficult time explaining their opposition to voters whose family budgets are being strained by fuel prices.

President Obama and some top Congressional Democrats have said they want to take some of an estimated $21 billion in savings from ending the tax breaks and steer it to clean energy projects. But the Senate’s Democratic leadership is calculating that using it to cut the deficit instead makes it a tougher issue politically for Republicans who are trying to burnish their conservative fiscal credentials.

“Big Oil certainly doesn’t need the collective money of taxpayers in this country,” said Senator Robert Menendez, Democrat of New Jersey, one of the authors of the legislation that Democrats intend to showcase. “This is as good a time as any in terms of pain at the pump and in revenues needed for deficit reduction.”