(Adds comment, detail; updates prices)
By Melanie Burton
MELBOURNE, March 24 (Reuters) - London copper was on Friday set to drop more than 2 percent for the week, with striking union members agreeing to return to work at the world's top copper mine, in Chile.
In the short term, investors were jittery on prospects that President Donald Trump's healthcare bill would not pass, suggesting he may not be able to muster the backing needed to push through fiscal measures central to the government's economic agenda.
"There was a lot of exuberance at the start of the year about President Trump's pro-growth policies and certainly base metals benefitted from that," said analyst Daniel Hynes at ANZ in Sydney.
"Certainly the talk around the Trump care vote today and obviously the implications for other policies like tax cuts are probably enough to push investors to the sidelines."
"At the moment there is no fear of a lack of supply even though we have massive supply side issues across the board."
* LME COPPER: London Metal Exchange copper had slipped 0.6 percent to $5,790 a tonne by 0311 GMT, erasing a small gain in the previous session. The metal was set for a 2.4-percent weekly drop, trimming year-to-date gains to near 5 percent.
* TECHNICALS: Copper faces resistance at its 200-day moving average on the weekly chart at $5,959 a tonne.
* SHFE COPPER: Shanghai Futures Exchange copper was little changed at 46,970 yuan ($6,816) a tonne.
* ESCONDIDA: The strike at Chile's Escondida, the world's largest copper mine, is ending after workers decided to invoke a rarely used legal provision that allows them to extend their old contract, the union said on Thursday.
* CHINA IMPORTS: China's refined metals imports were sharply lower in February, by 29 pct on the year for copper to 66 pct down for zinc, also spooking the market over the strength of demand.
* ZINC STRIKE: Noranda Income Fund said on Thursday zinc output at its Quebec plant, the second-largest in North America, was at 50-60 percent of normal operating levels as a five-and-a-half week long strike dragged on.
* JAPAN ECONOMY: Confidence among Japanese manufacturers rose for a seventh straight month in March to a three-year high, while the service sector's mood held steady, a Reuters poll showed, highlighting an export-led economic recovery.
* FREEPORT: Freeport-McMoRan Inc said Thursday that a nearly two-week strike has not materially impacted production levels at its Cerro Verde copper mine in Peru, the country's biggest, although the union said output has been cut in half.
* CHINA POLLUTION: Beijing and the surrounding province of Hebei will plant trees, establish green belts and make use of rivers and wetlands to create a "green necklace" to protect China's smog-hit capital from pollution.
* COMING UP: Euro zone Markit manufacturing flash PMI for March at 0900 GMT; U.S. durable goods for February at 1230 GMT.
Three month LME copper
Most active ShFE copper
Three month LME aluminium
Most active ShFE aluminium
Three month LME zinc
Most active ShFE zinc
Three month LME lead
Most active ShFE lead
Three month LME nickel
Most active ShFE nickel
Three month LME tin
Most active ShFE tin
ARBS ($1 = 6.8843 Chinese yuan renminbi)
Reporting by Melanie Burton; Editing by Richard Pullin and Joseph Radford