BOSTON — The tax fight between Mayor Michelle Wu and State Senator Nick Collins is back on, and this time Collins is accusing the administration of withholding the very numbers lawmakers need to evaluate Boston’s next property tax hike.

In a statement from his office, the South Boston Democrat said City Hall still hasn’t released the full valuation data behind this year’s tax proposal — even as the city moves to raise property taxes “during a time of financial strain.” Collins said he and other lawmakers can’t do their jobs without the numbers Boston is legally required to provide.

“We are asking the City to release the data,” the statement said.

The tension follows last winter’s dramatic standoff, when Wu tried to advance a property-tax shift at the State House that had already passed the City Council and the Massachusetts House. The plan died when Collins refused to move it through the Senate, citing unanswered questions, missing data, and the impact on small businesses and homeowners in his district. His move effectively killed Wu’s bill and forced City Hall to retreat.

Now, a year later, Collins is back in the middle of another tax firestorm — and he’s taking aim at two things: the withheld data and a new push from City Hall to weaken Proposition 2½, the law protecting residents’ right to vote on major tax increases. Collins’ office said any attempt to sidestep voters “is wrong,” and that he will continue to defend the public’s right to approve major tax changes.

But unlike City Hall, Collins isn’t just criticizing. He’s offering alternatives — actual policy tools meant to protect homeowners from the kind of tax spikes Boston is now facing.

One of those tools is S.1933, An Act to Prevent Property Tax Bill Shocks, which would let cities and towns offer a “tax-shock prevention credit” in years when residential taxes jump more than 10%. The credit would directly reduce bills for seniors, long-time residents, families on MassHealth, and households facing unemployment — effectively cushioning the hit when valuations swing too fast.

He’s also backing S.1935, An Act Relative to Municipal Tax Relief, which would allow Boston to issue rebates to residents who already qualify for the residential exemption. That gives local governments the ability to soften sudden tax increases without rewriting tax formulas or shifting burdens unpredictably.

Collins argues these bills offer real, targeted relief, not political sleight-of-hand or procedural shortcuts. He says they protect seniors and long-time residents, stabilize neighborhoods, and prevent the sudden “bill shocks” that blindside families when valuations jump.

Meanwhile, Wu’s team is pressing ahead with its tax plan — without giving lawmakers the numbers Collins says are critical to determining who gets hit hardest and why.

The dynamic looks a lot like last year: City Hall scrambling to justify a tax maneuver, and Collins demanding full transparency before anything moves forward.

For homeowners watching their bills climb, the contrast is stark. Collins is asking for data, relief, and straight answers. Wu still hasn’t released the numbers.