The European Commission has finalized new rules allowing member states the freedom to restrict or prohibit the import of genetically modified crops for food or feed, even if they have been approved by the EU legislative authority.

This proposal, which mirrors a directive issued by the EU in March covering the cultivation of GM crops, will now be sent to the European Parliament and the Council for a vote.

Under the latest rules, to opt out of approving an imported crop for domestic use, member states will have to provide reasons not already assessed by Brussels authorities, which currently include effects on human health and animal health and potential damage to the environment.

Suggested reasons could include local planning restrictions or lack of public consensus about the desirability of the product.

"The objective is to give national governments' view the same weight as scientific advice in the authorization of GMOs in their territory," Competition Commissioner Margrethe Vestager, standing in for Health Commissioner Vytenis Andriukaitis, said at a press briefing to announce the proposals.

A deadlock in GM crop approvals has been a major hindrance to their distribution in the EU up to now. Only one is currently approved for commercial cultivation, Monsanto's insect-resistant maize, MON 810, which is grown in Spain and Portugal.

Of the 129,000 hectares of GM maize grown in the EU in 2012, figures show that Spain accounts for more than 90%.

Currently, 58 GM crops are approved for use in feed and food. While very few are on sale for human consumption, an estimated 60% of the EU's requirements of vegetable proteins for cattle nevertheless are met by imported soy and soymeal from countries such as the US, where GM cultivation is widespread.

The US government and the European biotech industry have repeatedly complained about the EU's inaction in approving GM products. The association representing the interests of the biotech industry, EuropaBio, contends that the Commission has not cleared any crops since November 2013.

Additionally, GM crops are a point of controversy in negotiations between the EU and the US over the Transatlantic Trade and Investment Partnership free trade deal, TTIP. While the US wants Europe to open its doors to these products, many environmental and health advocates are vehemently opposed.

In a statement, US Trade Representative Michael Froman expressed disappointment over the Commission's plans to let EU national governments decide for themselves whether to allow GM imports. "Proposing this kind of trade-restrictive action is not constructive," he said, adding that it appears to divide the European trade bloc into 28 separate markets.

For their part, European environmental organizations are fearful that the proposed legislation does not provide a firm legal basis for member states to out, exposing them to legal challenges from biotech interests.

The right for companies to sue national governments seen as restricting trade is an especially controversial talking point, which has consistently held up TTIP negotiations.

A lack of a consensus about whether this right should be excluded from any deal is one of the reasons leading European politicians such as Germany's vice chancellor, Social Democrat Sigmar Gabriel, predict that the agreement may never be concluded.