The day after his 32-year term in the House of Representatives ended, Mr. Frank, a Massachusetts Democrat, said on Friday morning that he would like to be appointed as an interim senator to fill John Kerry’s seat until a special election later this year.

He would not run for election, he said on the MSNBC program “Morning Joe.”

It is up to Gov. Deval Patrick to name someone to fill the vacancy created by Mr. Kerry’s nomination to be secretary of state.

If selected, Mr. Frank would be a reliable liberal vote in a series of decisions on taxes, spending and the debt that face Congress this winter and spring.

He said it was those votes that had made him think twice about his earlier disinterest in the job.

Elizabeth Warren and Barney Frank representing Massachusetts in the Senate? Be still my liberal heart, that is a dream come true.