The Northern Ireland fishing industry believes there will be a compromise and not a sell-out when it comes to a future UK-EU fisheries deal, a Stormont committee has been told.
Representatives of the two main fish producers' associations gave evidence on Thursday.
UK and EU negotiators are meant to have done a deal by July although it is likely to be difficult and contentious.
The EU wants to retain existing access rights and quota shares.
The UK has said new arrangements will be necessary to reflect its position as an independent coastal state.
Speaking to MLAs on the Northern Ireland Assembly's Agriculture Committee, Alan McCulla of the Anglo-North Irish Fish Producers Association said fishing had become a "totemic" issue and a touchstone for the success of Brexit.
"The sense I have from politicians in London - and it is only a sense - is that there's no way they can afford to sell the UK fishing industry out," he said.
Harry Wick of the Northern Ireland Fish Producers Association said additional fish quota reverting to the UK could not simply be shared out based on the devolved administrations share of territorial waters.
MLAs were told Northern Ireland accounted for just 5% of UK waters and relied on fishing opportunities off Scotland and other areas outside the Irish Sea.
Mr Wick said his organisation favoured different options that would be fairer and apply to all, including those who were not members of any producer organisation.
Politicians were told that natural justice meant there should be a rebalancing of available stocks in the Irish Sea.
Mr McCulla said the Northern Ireland fleet took 80% of its catch from UK waters and 20% from the waters of the Republic of Ireland.
By contrast, vessels from the Republic took 70% of their most valuable catch - mackerel - from UK waters and 40% of prawns, the second most important catch.
Eighty percent of what Northern Ireland catches is sold in other markets, the biggest of them in Britain.