FARNBOROUGH — A bipartisan group of senators attending the Farnborough Airshow this week forecast a bleak outlook for a third reconciliation bill, warning that appropriators must take action to ensure the Pentagon’s base budget includes all the funds necessary for national security priorities.

The House this week is set to debate a budget resolution that would kickstart the reconciliation process and add $60 billion for defense — a number far less than the Pentagon’s $350 billion request.

But the lawmakers said even that will be a tough sell with midterm elections quickly approaching.

“There isn’t going to be a third reconciliation package. So anything that’s in there is not going anywhere,” said Sen. Jeanne Shaheen, D-N.H., a member of both the Senate Armed Services and Appropriations committees. “We need to be disciplined about the exercise of what’s a priority and what we’re going to fund.”

At an earlier media roundtable, Sen. Jerry Moran, R-Kansas, said he was “not certain there’s going to be a reconciliation bill that passes the House and the Senate.”