On the Hill, legislators have been fighting for months over how much of President Bush’s tax-cut plan they will approve. But even after they settle on a final figure, further tax cuts are possible.

Bush has been insisting on $726 billion in cuts, while the House, in early April, approved up to $550, and the Senate has rejected the idea of any cut higher than $350 billion. A few in both houses continue to say that any cut is irresponsible and will inflate the deficit.

But whatever number gets picked at the end of all the shouting will only be a guideline, not a legally binding limit. Other tax cuts may be proposed in later bills, and many on the Hill think the Republican congressional leadership may try to restore some of the cuts they agreed to do without.

“You may see one or two other tax items pass,” said Republican Rep. Christopher Shays, from Connecticut’s fourth district, last week.

According to Democrat Rosa DeLauro, “they are going to try to slice it up, cut it up, get it into a proposal where they can fit it all in.”

Some conservative observers say one of the best outcomes for the White House would be approval of a smaller tax number, like $350 billion, but one that would include the administration’s politically divisive proposal on dividends. Then other measures, like tax credits for married couples, children, or small-business owners, that are politically popular and more difficult for congressional moderates to oppose, could be pushed through in succeeding bills, they say.

Eric Engen of the conservative American Enterprise Institute has been suggesting that possibility for a while. After all, he said, “this is Washington D.C.”

The question is whether congressional Democrats would allow further tax bills to pass. Democrats could always filibuster in the Senate, but they’ve already been criticized for overusing that tactic to block two of President Bush’s judicial nominations.

And on a popular measure like tax cuts for small businesses, Republicans may be able to muster the 60 votes needed to break a filibuster anyway.

Democrats, in turn, have expressed outrage that Republicans may be strategizing to push through other tax-cut proposals after main debate on the president’s tax-cut plan. And they’ve proposed their own alternatives.

On Tuesday Senate Minority Leader Tom Daschle aired a $152 billion tax cut plan, and House Democrats released their own plan at a press conference Wednesday afternoon.

Another scenario, Engen said, would be for Congress to pass a large tax cut that would expire after just a few years, allowing it to fall below the Senate’s $350 billion figure, which is a 10-year estimate. That would leave some future Congress faced with the politically unsavory choice of allowing the tax cuts to expire and being blamed for raising taxes, or just extending the cuts, ballooning the deficit.

A proposal along those lines has been offered by Republican Sen. Charles Grassley of Iowa, who recommended a dividend tax cut that would expire in 2006. Other members of the Senate Republican leadership, including Olympia Snowe of Maine, have criticized the plan, saying they fear it would look like a gimmick to hide the true costs of the bill. Snowe, a moderate, has proposed an alternative plan that would exempt up to $1,000 of dividends from taxation.