Dutch voters will decide on Wednesday whether to support a European treaty deepening ties with Ukraine in a referendum that will test sentiment towards Brussels ahead of Britain’s June Brexit vote and could also bring a boost for Russia. The broad political, trade and defence treaty is already provisionally in place but has to be ratified by all 28 European Union member states for every part of it to have full legal force. The Netherlands is the only country that has not done so. While a “no” vote in the non-binding referendum would not force the Dutch government to veto the treaty on an EU level the fragile coalition, which holds the rotating EU presidency, might find it hard to ignore with less than a year to general elections. Any rejection by Dutch voters or by the government would give Russian President Vladimir Putin, who opposes deeper EU-Ukraine ties and who many Dutch blame for the downing by pro-Russian rebels of a plane travelling from Amsterdam, a victory in his war of words with the West. An EU decision to push on with the treaty despite a “no vote”, whether the government respects it or not, could be damaging for