A proposal aimed at bridging the split between whaling nations and their opponents will almost certainly come to governments for decision this year.
Sources say it could involve Japan accepting quotas below current levels; but Iceland is opposing proposed catch limits and an international trade ban.
Some anti-whaling countries see such a “peace package” as the only way to constrain whale hunting.
But others are likely to hold out for a complete end to the practice.
A small group of countries including the three active hunting nations – Iceland, Japan and Norway – and opponents such as New Zealand, Australia and Germany has been holding talks in Washington DC this week, exploring a possible compromise on quotas and other issues.
Following these talks, BBC News understands that a package is very likely to be finalised and lodged with the International Whaling Commission (IWC) by next Thursday – the deadline, under IWC rules, if it is to be debated at the June IWC meeting.
As yet, the package contains no agreed quotas; the chairman, Chilean diplomat Cristian Maquieira, is to insert suggested numbers over the next few days.
Sources close to the talks say Japan appears prepared to contemplate scaling back its annual Antarctic hunt to a size that anti-whaling nations might find acceptable.
In return, it would expect to gain catch quotas in the North Pacific waters close to its shores, which would benefit coastal communities where whaling is still practiced.
At the time of writing, Japanese representatives could not be reached for comment.
Although commercial whaling was banned in 1982, Japan hunts under regulations permitting whaling for scientific research, while Iceland and Norway lodged formal objections to the moratorium and so mount openly commercial operations.
Targets for criticism
However, if agreement between Japan and its opponents appears possible following two years of preparatory talks, there appears little scope for compromise on Iceland’s whaling.
“We have been showing good faith, but by presenting a moving target they are showing a lack of will to negotiate,” said Iceland’s IWC commissioner Tomas Heidar.
“You cannot negotiate with a moving target,” he told BBC News from Washington.
Last year, Icelandic boats caught 125 fin whales and 81 minkes – a significant increase on previous years, though still substantially below quotas in the years before 1982.
At a previous preparatory meeting, the anti-whaling side had proposed quotas of 60 fins and 60 minkes per year, Mr Heidar said.
Knowing these were not acceptable to Iceland, the anti-whaling bloc then lowered their offer still further, he related – subsequently adding the rider that under the new agreement, whales would have to be caught for local consumption only.
As Iceland’s ambitions include exporting fin whale meat to Japan, this was absolutely not acceptable.
International trade in whalemeat is banned, but Iceland, Japan and Norway have registered exemptions to the UN wildlife trade convention for some whale species.
The importance of international trade has been demonstrated in recent weeks by the interception in a Dutch port of an Icelandic whalemeat consignment apparently destined for Japan, the disclosure of a small export from Iceland to Latvia, the closure of a Los Angeles restaurant that was selling whalemeat, and a DNA study claiming to show that at least some of the meat sold there and in South Korea came from Japan’s scientific whaling programme.
The “peace package” would set terms for the next 10 years, with a review after five.
Initial quotas could be amended downwards if scientific assessments indicated the necessity.
Governments would agree not to set quotas unilaterally.
Whaling nations would have to agree to a monitoring regime involving observers on boats and a DNA register designed to keep illegal whalemeat out of the market.