Taiwan's main opposition party on Monday called for an immediate halt to a controversial plan to process the country's nuclear waste overseas.

Environmental activists said the plan by state-run Taiwan Power Co (Taipower) to ship the waste abroad runs the risk of a nuclear accident and an international backlash from campaign groups, AFP reports from Taipei.

The leading opposition of the Democratic Progressive Party (DPP) also weighed in with a promise to shoot down the plan as the government faces increasing pressure over its nuclear energy policy.

Taipower launched the bidding process for firms to transport and reprocess 1,200 spent fuel rods from two of the island's nuclear plants just before the Lunar New Year holidays, a tactic opponents said was to evade media and public attention.

The $356 million project still needs to be approved by parliament.

Companies from England, France and Russia have expressed interest in bidding for the proposal, local media reported.