Israel has escalated threats to invade the Gaza Strip over Palestinian rocket fire after planned economic sanctions drew objections from legal experts and foreign powers.

Since occupation forces withdrew from Gaza in 2005, Israel has mounted regular raids and air strikes on the territory, but has failed to stop rocket fire over the border.

And Hamas's de facto control of the strip since June, following Palestinian infighting with rival Fatah, has only stoked calls in the Jewish state for a big military sweep.

Speaking to reporters on Tuesday, Ehud Barak, Israel's defense minister, said: "Every passing day brings us closer to a broad operation in Gaza. We are not looking forward to it [and] we would be happy if circumstances prevented it."

Israel, which controls official Gazan border crossings, began reducing the amount of fuel pumped to Gaza this week. It also wants to reduce power supplies, but has put that on hold.

'Collective punishment'

The sanctions, which were put together by Barak, prompted UN and EU delegates to urge Israel not to impose "collective punishment", illegal under international law, on Gaza's 1.5 million residents.

Israel's attorney-general also opposes cutting electricity supplies to Gaza on humanitarian grounds.

Britain said on Tuesday it was "deeply concerned" by reports that Israel had reduced Gaza's fuel supply and was considering electricity cuts, and had spoken to the Israeli government about the matter.

Makeshift Palestinian rockets have killed two Israelis this year.

Hamas has not claimed recent attacks, but Israel's military says Hamas is carrying out an arms build-up that will make it a serious fighting force.

Weighed against an invasion of Gaza is a US-organized peace conference in November between Ehud Olmert, the Israeli prime minister, and Mahmoud Abbas, the Palestinian president, who affectively only rules the occupied West Bank.

While Olmert may want calm, he is also under pressure from right-wing coalition partners to hit Hamas hard.

Haim Ramon, Israel's vice prime minister, when asked about a possible Gaza invasion, said: "The present situation will not last."

"I prefer that we use sanctions. I believe that the implementation of sanctions will be effective. But we have our doubts about it."

In the interview with Reuters news agency, he added: "If they stop sending rockets over, our need for the weapons of sanctions, or other weapons, will not be an issue."

PHOTO CAPTION

Ehud Barak, Israel's defense minister