The rising tide of public opposition to nuclear power in the wake of the Chernobyl disaster is posing serious political risks for conservative governments in West Germany and the Netherlands as they approach important elections in coming weeks.

As radiation levels in Western Europe have subsided in recent days, the political aftershocks are still reverberating most acutely in Bonn and The Hague, where center-right ruling coalitions now confront revived antinuclear challenges after successfully coping with emotional protests against the deployment of new nuclear missiles.

In the Netherlands, the government of Prime Minister Ruud Lubbers decided last week to abandon a program of building up to four new nuclear reactors in the next decade to generate one-third of the country's power from nuclear energy.

The decision to halt the expansion of nuclear power plants followed the publication of opinion polls showing that support for Lubbers' coalition was fading rapidly as public hostility to nuclear power grew more intense after Chernobyl.

The latest polls suggest that the ruling coalition of Christian Democrats and right-wing liberals will lose its majority in national elections on May 21. The opposition Labor party, which is staunchly opposed to nuclear energy and wants to shut down the country's two existing plants, is now expected to win the largest share of the vote but may fall short of an outright majority.

Labor's return to power could spell not only a radical shift in the country's energy policy, but also in its defense commitments.

The Laborites insist they will abort plans to deploy cruise nuclear missiles in the Netherlands beginning in 1988, a commitment that parliament approved last autumn after six years of complex political maneuvering.

In West Germany, Chancellor Helmut Kohl's government has come under renewed fire for its unwavering support of nuclear power, including an expansion of the country's 19 nuclear power stations and the building of a controversial nuclear reprocessing plant near the Bavarian village of Wackersdorf.

The country's antinuclear alliance, led by the radical Greens and left-wing Social Democrats, has come to life again after lapsing into despondency following its failure to thwart the installation of new Pershing II nuclear missiles.

In Munich last week, more than 15,000 demonstrators brought traffic to a standstill for an hour. In Lower Saxony, where a crucial state election is due to be held on June 15, about 6,000 people protested against a planned nuclear waste dump at Gorleben.

The iconoclastic Greens party, which demands the closure of all nuclear plants, has adopted the new rallying cry "Chernobyl is everywhere."

The surge in antinuclear sentiment has boosted the party's support to more than 9 percent, and the Greens now appear likely to end up holding the balance of power in Lower Saxony.

A loss there by the Christian Democrats would cost Kohl's center-right coalition its majority in the upper house of parliament, or Bundesrat, and give the opposition Social Democrats the opportunity to block all legislation.

It would also deal another blow to Kohl's prestige and call his personal authority further into question.

The opposition Social Democrats, who once backed an active nuclear energy program when they held power at the national level, have sought to capitalize on swelling public resentment toward nuclear power by endorsing a policy of freezing all nuclear energy development until a transition to other forms of power can be carried out.

But in spite of post-Chernobyl surveys that show 69 percent of the voters opposed to the government's pronuclear policies, Kohl has refused to soften his stance.

"What we need now is not a German withdrawal from nuclear energy but the start of international efforts to achieve more nuclear security," Kohl told parliament on Wednesday.

Amid jeers and catcalls from the Greens representatives, Kohl contended that nuclear reactors were more benign sources of energy in terms of environmental dangers than fossil fuels.

The West German government has offered to host an emergency conference of all nations that use nuclear power plants with the goal of ensuring tighter safeguards throughout the world. Kohl also criticized Moscow's "lack of any sense of responsibility" to inform Soviet citizens and neighboring countries about the nature of the Chernobyl accident.