ZURICH (Reuters) - A right-wing proposal to cement Swiss sovereignty on legal matters over international law is headed for defeat in a binding referendum this month as opposition mounts, final polls released on Wednesday showed.

Should the measure fail under the Swiss system of direct democracy, it could revive stalled negotiations between Switzerland and the European Union on a new umbrella treaty by the end of the year.

The Swiss government has urged voters to reject the “Swiss Law, Not Foreign Judges” drive in the vote on Nov. 25, saying it would force it to cancel treaties, weaken human rights protections and hurt the economy.

The Swiss People’s Party (SVP) -- the biggest in parliament and with two seats in the seven-member cabinet -- has pushed the idea. It sees a need to anchor the supremacy of domestic law so that regular citizens can wrest control from political elites.

But the message does not seem to resonate with voters.

A Tamedia survey showed 58 percent of respondents opposed the plan, five points more than in the previous survey, while a poll for broadcaster SRF put opposition at 61 percent.

“If the trend continues, a very clear ‘no’ is expected,” gfs.bern pollster Lukas Golder told SRF.

If that is the case, the ballot-box blow to isolationism could boost the currently slim prospects for a treaty with the EU setting out Switzerland’s ties to its biggest trading partner.

Chances of a deal appeared to fade last month when negotiators could not reach a breakthrough after four years of talks. Neither side has declared the talks dead, however.

Defeat for the SVP plan could offer momentum for a last push, especially if Britain can nail down terms of an orderly exit from the EU, which has been loath to show too much flexibility to the Swiss for fear of encouraging Brexiteers.