Fishermen will be paid to catch plastic, rather than fish, under bold new plans from the EU's fisheries chief, aimed at providing fleets with an alternative source of income to reduce pressure on dwindling fish stocks.

Maria Damanaki, commissioner for fisheries, will unveil a trial project in the Mediterranean this month, which will see fishermen equipped with nets to round up the plastic detritus that is threatening marine life, and send it for recycling.

The move is intended as a sweetener to fishermen who have bitterly opposed the European commission's plans to ban the wasteful practice of discarding edible fish at sea. Fleets fear they will lose money by not being able to throw away lower-value catch.

Damanaki vowed yesterday to press on with her plan to eliminate discards, citing the strength of public opinion on the issue, whipped up in large part by the Fish Fight campaign waged by the food writer Hugh Fearnley-Whittingstall. Two-thirds of the fish caught in some areas is thrown back, usually dead, because fleets exceed their quota, unintentionally catch juveniles or species for which they lack a quota, or because they prioritise higher value fish and throw away lesser species. About 1 million tonnes are thrown back each year in the North Sea alone.

"Ending this practice of throwing away edible fish is in the interest of fishermen, and consumers," Damanaki told the Guardian in an interview. "It has to happen – we cannot have consumers afraid to eat fish because they hate this problem of discards."

But she acknowledged: "People [in the fishing industry] feel insecure, because this is a change. That is why they need incentives."

Fishermen who clear plastic will be subsidised initially by EU member states, but in future the scheme could turn into a self-sustaining profitable enterprise, as fleets cash in on the increasing value of recycled plastics. Cleaning up the rubbish will also improve the prospects for fish, seabirds and other marine species, which frequently choke or suffer internal damage from ingesting small pieces of non-biodegradable packaging.

In a boost to Scottish fishermen, Damanaki also said she was seeking a legal instrument that would allow the EU to ban imports of fish products – such as fish oils and fish meal – from countries that did not meet high sustainability standards. This would help to level the playing field, she said, between EU and non-EU fleets. It would also deprive Iceland of a significant export market, and cheer Scottish fleets who have complained that Icelandic fishermen have too high a quota of mackerel, putting huge pressure on the shared stock.

This month, Damanaki will also seek to tackle a growing source of conflict with developing countries over fishing rights. At present, several EU fishing fleets take large amounts of their catch from the seas around Africa and the Indian Ocean. They are able to do so because of secretive agreements on fishing rights, struck with developing country governments.

As a result of these, campaigners complain that the EU boats are depriving fishermen in poor countries of their potential catch, and stifling the growth of indigenous fishing industries that could boost developing economies.

On 13 May, Damanaki will hold the first meeting of ministers from developing countries aimed at redrawing these controversial fishing access plans. She said: "There needs to be more transparency. We have to recognise that people have the right to establish their own control mechanisms on their own industry. We have to cooperate to find a way to deal with the problem of overfishing."

But the scale of the opposition Damanaki will face to her key proposals on discards was on display at a hearing in Brussels on Tuesday, when fishing representatives attacked the measures. One said: "The consequence of this will be a much, much smaller fleet." Another said it was not possible to end discarding completely.

An alternative being touted by some member states is to make the phasing out of discards voluntary. But Damanaki rejected this outright, saying it would be no different from the current situation. "We have been talking about discards for more than a decade. Now we need radical reform. Time is running out," she said.

Damanaki has the support of several key member states, including UK, Germany, France and Denmark. She will publish her formal proposals in July, for debate by the European parliament and council.