A war of words has broken out between Edinburgh and London after English fishing authorities accused the Scottish government of launching a “pre-emptive strike”, by “illegally” blocking trading of fishing quotas between Scotland and England.

The row erupted as fishing leaders denounced a move by Richard Lochhead, the Scottish Cabinet Secretary for Rural Affairs and the Environment, to impose the ban pending consultations on a new catch regulation system. Under the system, boat owners can transfer quotas worth up to £5million per vessel.

Jonathan Shaw, the UK Fisheries Minister, described the action as “unilateral” and added that it amounted to the “tearing up of long-standing agreements”. Mr Shaw also questioned the legality of the move.

But the Scottish government justified the move as ensuring that Scotland's fishing rights remain with fishermen in Scotland.

Behind the row is the expectation that the UK Government is prepared to go along with Brussels' proposals for fully tradeable quotas, seen as a way of ending the scandal of fish being discarded at sea because a catch is outside an allowance. Some fear this would result in large Spanish or Icelandic owners buying up Scottish quotas.

The SNP administration took pre-emptive action after failing to persuade London to agree to block Brussels in behind-the-scenes talks.

The tensions between the two governments comes at a period of difficult relations between the administrations which started with London's dismissal of Mr Lochhead's demands to represent the Scottish fishing industry in negotiations in Brussels.

It was last Friday that the Scottish government announced that it had frozen the trading of quotas registered in Scotland to stop them being sold to buyers south of the Border.

The move prompted outrage from English fishing groups, the Westminster government and Scottish fishermen. The National Federation of Fishermen's Organisations described it as part of a “separatist agenda” by the SNP-led government, and labelled the move as “provocative, highly irresponsible and probably illegal”.

Barrie Deas, chief executive of NFFO, said: “This is undemocratic and will adversely affect many of the NFFO's members whose vessels happen to be registered in Scotland. There is no such thing as a Scottish or English quota. There is a UK quota. There is no basis in law for the Scottish Executive to apply unilateral measures that will have serious consequences across the UK industry.” He claimed that attempts to divide the Scottish and English industries were illogical. “If fishermen in Scotland go over their quota, fishermen in England are affected. You have to have co-operation.”

Until last Friday fishing quotas could be traded within and across the UK, and they are used to secure loans and as collateral against bankruptcy. There are fears that if they cannot be sold outside Scotland, the quotas will lose their market value.

Jim Portus, of the UK Association of Fish Producers' Organisations, hinted that Mr Lochhead might be liable for legal action for unlawful restraint of trade. George MacRae, of the Scottish White Fish Producers' Association, said there was “every reason to suggest it is illegal”.

But Iain MacSween, of the Scottish Fishermen's Organisation, said it was “entirely reasonable and lawful” for Scotland to define and organise its own quotas.

A Scottish government spokesman said: “The proposals we are publishing will safeguard Scotland's traditional fishing rights for future generations. That is why our consultation is being welcomed by many fishermen and others involved in this vital sector. Claims by the UK Government that we are creating uncertainty are tantamount to scaremongering.”