Public backing for a ban on discarding edible fish at sea has been thwarted by the reluctance of the fishing industry and the government to put an end to the wasteful practice, the House of Lords has found.

Discards were officially banned in January, after a five-year phase-in period, but the practice appears to have continued, with the government failing to take action, said a Lords EU energy and environment subcommittee report.

Lord Krebs, a committee member, told the Guardian: “Everyone thinks [the discard ban] is a great idea, and a part of sustainable fishing. But we found fishermen were not aware of it or not implementing it, the enforcement bodies were not enforcing, and the solutions not being used.”

About 1.7m tonnes of fish are discarded across the EU every year, because fleets catch fish for which they do not have a quota, or have already exceeded their quota, or because they throw back fish judged to be of low commercial value. The new “landing obligation” under the EU common fisheries policy means fleets must bring ashore all they catch, whether it is commercially valuable or not.

But this can mean fishermen run out of key species quickly. The Lords heard evidence that some vessels could run out of their annual quota as soon as February, while George Eustice, minister for agriculture, fisheries and food, admitted some could run out by June.

The evidence strongly suggested fishermen would not adhere to the new rules, said Krebs. “Although the landing obligation has applied to a number of UK fish stocks since 2015, we heard no evidence that fishers have been complying with it, or that any serious attempts have been made to enforce it,” he said.

The Lords recommend measures such as more selective fishing gear, better technology to track in real-time where shoals of particular species are to prevent vessels pursuing the wrong fish, and remote electronic monitoring of vessels, by CCTV and other means, to show whether they have complied with the rules. There should also be easier methods for fishers to swap quota among themselves.

Krebs said the UK government was unwilling to enforce the rules strictly when other member states appeared not to be doing so, as that could put British fishermen at a disadvantage.

He suggested a compromise by which the large vessels that take 94% of the UK’s total catch should be made to submit to remote monitoring, as they were in a better position to afford the equipment, while the smaller boats which make up more of the fleet but take only 6% of fish could be allowed more time to comply.

The focus should now move to supermarkets selling fish to the public, Krebs said. “Retailers are the key to this. If retailers said we will not sell fish from boats we do not think are meeting the landing obligation, that would bring a big change.”

Discards have long been a source of public concern, and in 2011 the European commission began the process of phasing out the practice. A public petition in the UK gathered more than 870,000 signatures, and new EU rules were brought in from 2013, with discards phased out from 2015 until the final ban this year.

The practice became a flashpoint issue during the EU referendum campaign, with the leave camp highlighting the resulting waste of fish as an example of EU failure. A fisheries bill setting out how the UK will manage its stocks after Brexit also aims to prevent fleets discarding fish.

Barrie Deas, the chief executive of the National Federation of Fishermen’s Organisations, blamed non-compliance on the current ban’s flawed design, which he said failed to account for “choke” species. These are species for which there is low quota or no quota, but which are often found in mixed fisheries near commercially valuable stocks.

“The problem of chokes in mixed fisheries is largely unresolved,” he said. “Fishermen would be happy with a workable discard ban – understandably, they are not happy with a landing obligation that jeopardises their livelihoods.”

After Brexit, Deas pointed out, the fisheries bill contains a potential system under which catch landed beyond a vessel’s quota would be landed but subject to a charge, which would discourage fishermen from pursuing such fish.

Griffin Carpenter, a senior researcher at the New Economics Foundation thinktank, said the evidence from fishing ports suggested a lack of compliance with the ban. “Although the campaign to end discarding came from the UK, it is now policy across the EU that all fish caught must be landed – even undersized catches.

“The fact that we aren’t seeing undersized fish coming into ports shows that we have no idea what is happening at sea and no real mechanism to enforce the policy. For fishers there is little incentive to limit discarding and a great unfairness for those who already have.”

A spokesperson for the Department for Environment, Food and Rural Affairs said: “The government remains fully committed to sustainable fishing and ending the wasteful discarding of fish. We secured a deal [with the EU] to ensure there are workable solutions to support fishermen to comply with the changing regulations. Our fisheries bill introduces powers to create new schemes to help seize the opportunities of becoming an independent coastal state, [including] helping the fishing industry comply with the landing obligation.”

The Lords committee took evidence for its inquiry up to last November, before the full ban came into force but while many UK fisheries were covered by partial bans. Krebs said it was unlikely that there had been a material change in practice since 1 January.