Although they regard Israel's settlements as a threat, tens of thousands of Palestinians such as Mohammed Ali, 26, a labourer, fear their families would starve without them.

Every morning he and dozens of other informal workers huddle near the entrance of Ma'ale Adumim, one of the largest of roughly 120 rapidly expanding settlements in the West Bank. The men wait for offers to paint Jewish houses or manicure gardens. The odd jobs can pay quadruple what they would earn in nearby Palestinian communities - that is, if they can find any work there at all.

So when the Palestinian Authority (PA) last year banned Palestinians from working on settlements, Mr Ali and company were infuriated.

"What do they expect me to do? Should I sit at home while my water and electricity bills grow bigger and bigger?" said Mr Ali, a father of five who lives in Bethlehem.

His predicament exemplifies the daunting challenge the PA faces in trying to cope with Israel's occupation. While its boycott of goods produced in the settlements has popular support, prohibiting work on them - with the threat of hefty fines and a prison term - has proved controversial.

The PA hopes the measures will inflict economic pain on the settlements. They are also meant as acts of conscience.

"It is immoral for us - totally immoral for us - to work in settlements," Hassan Abu Libdeh, the economics minister and proponent of the law, said last year.

Since then, however, the calls to conscience have been muted by the concerns of people like Mr Ali.

"If the PA wants to stop us from working here, then it should give us jobs or help us with all the millions of dollars they get from America and Europe," he said.

Indeed, citing difficulties in creating alternative jobs, the Israeli daily Haaretz reported last month that the PA had reconsidered the ban. Pushing more than 20,000 Palestinians out of their settlement jobs and into uncertain economic conditions could lead to unrest.

While down playing the story, PA officials have acknowledged there are few other options for Palestinians working on settlements.

"There is an intention to do this and there is a law" against working on settlements said Ghassan Khatib, a PA spokesman, "but we have to do a lot more work in providing alternatives to workers."

Mr Khatib said officials would refrain from punishing settlement workers and, simultaneously, explore alternatives, including a $100 million (Dh367m) aid package designed to draw Palestinians from their jobs in settlements.

Still, creating jobs for all of them could take many years, said Samir Abdullah, the director general of the Palestine Economic Policy Research Institute. Israel's control over much of the West Bank, tepid investor confidence in the Palestinian economy and a rapidly growing labour force present significant challenges for the people who are trying to create enough jobs in the West Bank, he said.

"The Palestinian economy simply isn't in a position to absorb all these workers," he said.

Palestinians were once a mainstay of Israel's work force, holding jobs in construction, agriculture and nursing. After the start of the second intifadah in 2000, however, Israel began weaning itself from its reliance on Palestinian workers, replacing them with labourers mainly from Asia.

In 2009, there were an estimated 220,000 foreign workers in Israel, about half of whom were illegal, according to Israel's Central Bureau of Statistics. Settlement construction may represent one of the last Palestinian toe-holds in the Israeli labour force.

Waleed Assaf, a member of a Palestinian Legislative Council committee that deals with Israeli settlements, said it was imperative for Palestinians to avoid contributing to the settlements but said the PA lacked a coherent strategy to do it.

A practical solution, he suggested, would be to first concentrate on finding alternative work for construction workers and then target those who work in agriculture and industry. "First and foremost," he said, "we have to stop those who are building the settlements and allowing them to expand on our land.

Mr Assaf, however, acknowledged that alternative jobs would probably involve a pay cut - requiring from people "a little sacrifice for our future".

Dror Etkes, an Israeli expert on settlements, is sceptical that Palestinians would make such a sacrifice, since settlement salaries are "four to five times higher". And because of restricted access inside Israel itself and the pressure created by a growing Palestinians labour force, many have no real choice but to find settlement work.

"I estimate that 95 per cent of the labour in West Bank settlements is Palestinian," he said.

"The other problem is that Israel is compensating these companies because, in the Israeli national budget, there is a chapter that compensates companies for any kind of boycott imposed against them," he said.

Settlers agree. Since calling the PA boycott a "hostile act" and pleading with the Israeli government to close its ports to Palestinian goods last May, they now seem far less concerned.

"I'm not aware of that many, if any, businesses that have shut down because of the boycott," said Naftali Bennett, the director of the Yesha Council, an organisation that represents settlements.

"In fact, I visited a factory last week that had 10 per cent of its sales affected internally, but they simply shifted their market focus to Israel and abroad to make up for the damage."

He was also sanguine about the ban on Palestinian workers.

"Let's say an average Palestinian family is six or seven people, and one worker supports two families, so you have on average, let's say, a total of 15 people dependent on him," Mr Bennett said.

"Now multiply 15 people by 30,000 workers - the answer means that nearly half a million Palestinians are supported by, and in need of, the Palestinians in our factories."

Back in Ma'ale Adumim, Palestinian labourers agreed, however reluctantly, with Mr Bennett's logic.

Sitting on the grass near the entrance, a 50-year-old Palestinian man, who gave his name as Abu Mohammed, put their predicament succinctly: "We don't want to work here. We don't like the occupation. But what do you expect us to do?"