THE HAGUE, Netherlands — A left-wing environmentalist party scored strongly in key Dutch municipal elections Wednesday, exit polls suggest, while a referendum on a law granting intelligence agencies far-reaching powers to tap electronics communications was too close to call.

Exit polls conducted by Ipsos in six of the Netherland’s 335 municipalities and cited by Dutch media had the Green Left emerging as the biggest party in Amsterdam and the central city of Utrecht. Green Left scored strongly in national elections last year, but did not join Prime Minister Mark Rutte’s four-party ruling coalition.

“What has happened is historic,” party leader Jesse Klaver said. “Not all the votes have been counted, but this can be a beautiful night.”

Final results were expected Thursday.

Municipal elections in the Netherlands are more heavily influenced by local issues such as parking problems and garbage collection than by national matters and messages.

The non-binding referendum to gauge voter’s views on the new intelligence agency law was on a knife’s edge.

An Ipsos poll said 49 percent of voters were in favor of the law and 48 against, but had a 5 percent margin of error. The poll suggested a turnout of 48 percent, well above the threshold of 30 percent necessary for the referendum to be declared valid.