Four tankers have been cleared to cross the Bosphorus on Monday to help end a backlog of tankers stalled by Turkish demands for insurance cover.

The country’s maritime authority obtained the necessary letters following behind-the-scenes talks late last week.

The authority also said that it had removed five oil tankers from its territorial waters via the Dardanelles as they could not produce insurance letters providing confirmation of cover.

More than 20 fully-laden tankers had been left waiting to pass through the narrow waterway while Western protection and indemnity clubs tried to thrash out a deal with the Turkish authorities.

Turkey had demanded extra assurances of coverage from 1 December in case of accidents, after the introduction of a price cap scheme by the G7 group of countries. The waterway crosses Istanbul, a city of 20 million inhabitants.

The International Group (IG) of P&I clubs, however, refused to meet the additional requirement, saying it ran against its principles.

According to Turkish authorities, however, at least one IG member accepted to provide the requested letter and a Turkish-flagged tanker was allowed to cross.

The compromise text allowing the passage has been submitted for consideration to other clubs as well. According to shipping sources, it states stating basic voyage, ship and cargo data and confirms the existence of P&I coverage.

The text, however, also says that the requested confirmation doesn't warrant the accuracy of any information provided to the Club, or any indemnity or evidence of any undertaking on the part of the Club to any other third party.

Turkey has argued that breaches of the price cap could mean that tankers lose coverage and complicate any clear-up after a spill. The government in Ankara fears that a sanctioned cargo in breach of club rules might allow P&I providers to refuse cover in case of accidents.

Failure to coordinate with stakeholders before the measure was announced, however, as well as recalcitrance on all sides after it entered into force, led to a stand-off in which even the US government intervened, urging Ankara to back down.

Shipowners covered by IG clubs protested that the whole situation had led to absurd results, as alternative P&I providers — including those from Russia or others of questionable origin — had little qualms to comply with Turkey's request.

Tankers leaving Russia’s Black Sea Ports need to pass through the Bosphorus Strait and Dardanelles to reach the Mediterranean Sea for onward voyages to Asia.

The US government last week urged Turkey to drop its new practice of demanding additional protection and indemnity certification for tankers.