A special election for the Second Hampden and Hampshire Senate seat last held by Westfield Mayor Don Humason has been delayed until May Tuesday, May 19. 

Special elections were originally scheduled for March 31 to fill two House and two Senate seats, including Humason’s old seat, but last week, as the spread of the coronavirus and the precautions around it both intensified in Massachusetts, Senate President Karen Spika and House Speaker Robert DeLeo announced plans to delay the votes. The Senate set the new date for its two elections via an order it adopted Monday afternoon, while the House adopted a pair of orders setting June 2 as the new date for elections to fill its two vacant seats.

In all four races, primary voters have already decided the party’s nominee, leaving the general special elections remaining.

In western Massachusetts, Rep. John Velis, a Westfield Democrat, and Westfield Republican John Cain are squaring off for Humason’s old seat. At the other end of the state, in the Plymouth and Barnstable District, the candidates are Falmouth Democrat Susan Moran and Bourne Republican Jay McMahon. Viriato deMacedo resigned the Senate seat last fall for a job at Bridgewater State University.

The House seats to be filled were last held by Taunton Republican Shaunna O’Connell and Lunenburg Democrat Jennifer Benson, who each resigned for new positions.

O’Connell was elected mayor of Taunton. Democrat Carol Doherty and Republican Kelly Dooner, both of Taunton, are now vying for her Third Bristol District seat, which also represents a precinct in Easton.

In the 37th Middlesex District, where Benson vacated her seat to become the head of the Alliance for Business Leadership, the contest is between Acton Democrat Danillo Sena and Lunenburg Republican Catherine Clark. The district includes Boxborough, Shirley, Harvard and parts of Acton, Ayer and Lunenburg.

Lawmakers on Monday also sent Gov. Charlie Baker a bill (S 2608) that would allow cities and towns to postpone municipal elections scheduled for this spring. That bill also includes language specifying that “any eligible voter may vote early by mail for any annual or special municipal or state election held on or before June 30, 2020.”

A third House seat remains vacant almost three weeks after the election to fill it. Representative-elect Kate Lipper-Garabedian, a Melrose Democrat, on March 3 prevailed in the race to succeed now-Melrose Mayor Paul Brodeur in the House. Amid the closures, cancellations and restrictions driven by the coronavirus pandemic, Lipper-Garabedian has not yet been sworn in.

Like in the Senate, Democrats hold a supermajority in the House, currently accounting for 125 seats — 126 once Lipper-Garabedian officially joins the body — to the Republicans’ 31.