The British Government has decided that two former US Navy ships contaminated with chemicals will have to return to America.
The Environment Secretary Margaret Beckett said the ships would be temporarily stored at Hartlepool before going back across the Atlantic, because it was the safest option.
They were due to be dismantled at the port.
A decision on two other ships currently bound for the UK, which make up the controversial so-called 'ghost' fleet, has yet to be made.
The first two ships in the 13-strong convoy today passed within 200 miles of the Irish coast, south of Cork.
The Minister for the Marine, Dermot Ahern, was to raise the Government's objections to the convoy with the British Ambassador at a meeting next week.