ZURICH, June 12 (Reuters) - The Swiss upper house of parliament asked the government on Wednesday to get more concessions from the European Union over a draft treaty, raising the stakes ahead of a mid-June deadline Brussels has set for a final deal.
Swiss failure to endorse the treaty and begin ratification could damage ties with its biggest trading partner, disrupting commerce and cross-border stock trading.
The Bern government last week said three issues - wage and worker protection, state aid and citizens' rights - needed clarification before it could sign the accord negotiated over more than four years.
Upping the ante, the upper house on Wednesday added two more topics - details on resolving conflicts and giving Swiss voters a final say on amended laws - and urged the government to pursue "additional negotiations or other appropriate measures".
European Commission President Jean-Claude Juncker said on Tuesday he was ready to clarify any doubts but the November 2018 draft treaty would not be renegotiated.
It is unclear whether stepped-up diplomacy might lead by next week to extending provisional recognition of Swiss stock exchanges as "equivalent" to EU bourses.
That designation allows Swiss exchanges to access the EU single market but expires at the end of June.
"The Lord may have created the world in seven days, but that really is unrealistic (with respect to the EU deadline)," Christian Democrat lawmaker Pirmin Bischof told broadcaster SRF.
The treaty would have non-EU member Switzerland routinely adopt EU single market rules and make possible new trade deals, such as for an electricity union.
Swiss media commentators suggested it would be easier to forge compromise language on the issues of state aid and citizens' rights than on the Swiss system of using spot checks to ensure cross-border workers do not undermine high Swiss pay.
"We are not against the treaty in principle but it is clear that the Swiss government and negotiating team must guarantee that we can defend our pay independently," labour union official Daniel Lampart told SRF.
Britain's separate negotiations on its EU divorce terms complicate matters. The Commission is loath to be soft on the Swiss for fear of encouraging hardline Brexiteers demanding a renegotiation of Britain's withdrawal accord.
Unlike the messy Brexit divorce, Switzerland has a patchwork of 120 sectoral accords that govern EU ties and which would remain in the absence of a new treaty. But they will become increasingly outdated as single market rules evolve. (Reporting by Michael Shields Editing by Mark Heinrich)