WASHINGTON — Ignoring veto threats from President Bush, House Democrats are awarding huge budget increases to veterans and homeland security programs as they begin advancing spending bills for the next fiscal year.

In rapid succession, House panels have raised the Veterans Affairs Department’s budget a record 18% — an increase exceeding even what difficult-to-satisfy veterans groups wanted — and the Homeland Security Department’s budget by 7%.

The $43.2 veterans budget approved unanimously yesterday by a House subcommittee followed another panel’s endorsement last Friday of $36.3 billion homeland security budget for the 2008 fiscal year beginning October 1.

While both are well above Mr. Bush’s requests, Democrats are calculating that the president will have difficulty in carrying out his threats to veto the bills for busting his budget.

The White House recently issued a blanket veto threat against bills funding domestic agency budgets that break budget limits issued by Mr. Bush in February.

Given the great popularity of veterans and homeland security programs with lawmakers and the public, Democrats are gambling that Mr. Bush will spare those two programs from his veto pen. Some even entertain the possibility of overriding a veto with two-thirds majorities in each House.

The increase in veterans programs is viewed as especially bulletproof following recent revelations about poor conditions at Washington’s Walter Reed Army Medical Center and 18-month waits for many veterans trying to access VA medical care.

“This bill send a clear message to America’s servicemen and women, their families, and our veterans that a grateful nation deeply respects their sacrifice and service,” said Rep. Chet Edwards, a Democrat from Texas.

Despite the eye-popping increases for veterans, not a single Republican on the House appropriations subcommittee approving the bill yesterday expressed reservations about it.

The bill more than doubles Mr. Bush’s request for construction and repair of VA facilities. It also would pay for hiring more than 1,000 new claims processors to ease a backlog of 400,000 claims from veterans.

The homeland security budget includes big increases for bomb detectors at airports while doubling grants to state and local governments for upgrading security for mass transit systems and at vulnerable ports. Unlike the veterans measure, it did attract some GOP opposition.

“Homeland security is not a problem that can simply be solved by more money and more government,” said Rep. Hal Rogers of Kentucky, former chairman of the appropriations subcommittee for homeland security.

Yesterday’s panel session was punctuated by a nettlesome exchange between Appropriations Committee Chairman David Obey, a Democrat from Wisconsin, and its senior Republican, former chairman Jerry Lewis of California.

Mr. Lewis complained that the veterans bill — which also funds military housing and base improvements — does not specify which of the hundreds of such projects will be funded next year.

Instead, such earmarks won’t be disclosed until a final bill emerges from a House-Senate conference panel this summer or fall. Republicans pointed out that new House rules pushed through by Democrats require greater transparency about earmarks requested by lawmakers.