The City of Manchester has a spending cap. And the economy is bad. So naturally aldermen voted overwhelmingly to spend close to $1 million on more city employees.

On Tuesday night, the aldermen voted to accept federal grants to hire eight new firefighters and five new police officers. Though they thought they were doing the city a favor, they really were falling — again — for an old congressional trick.

It goes like this: Congress funds local police officers and firefighters (and sometimes teachers and other municipal employees) for a few years, but in exchange for the money, the municipality has to spend its own money on those positions in one or more later years. The irresponsible spenders in Washington bet that cities and towns will not lay off the new hires when the federal money runs out. The result: more government employees, higher government spending, higher taxes.

Aldermen voted 10-4 to accept the firefighter grant, which would use federal money of $561,000 in 2013 and $575,000 in 2014. The city would pick up the 2015 tab, estimated at $600,000. But Mayor Ted Gatsas says it is bigger than that. “They say that a firefighter starts at a step 17 grade 1, which is about $43,000,” he told us. “But that doesn’t include retirement contributions and other things. His actual pay is about $50k. I think the number’s going to be closer to $750,000.”

Then there is the police grant. Aldermen voted 11-3 to accept that one. It would obligate the city to pay about $18,000 in 2013, $50,000 in 2014, $50,000 in 2015 and $233,000 in 2016, according to the city finance director.

These are new hires, which the city almost certainly cannot afford.

Mayor Gatsas was right to veto both votes, though he knew the aldermen would override him. And Aldermen Phil Greazzo, Joe Kelly Levasseur, Jim Roy and Bill Shea (Shea voted against the fire grant but for the police one) were right to cast their “no” votes.