Foreign Secretary Jeremy Hunt has hit back at Jeremy Corbyn after the Labour leader accused the Government of fuelling conflict with Iran.
Mr Corbyn said Britain should not be stoking a military escalation in the Gulf without "credible evidence" Iran was behind the attacks on two oil tankers which dramatically heightened tensions in the region.
In response, Mr Hunt – who has said it was "almost certain" Tehran was behind the attacks – accused him of persistently failing to stand up for British interests and British allies.
"Pathetic and predictable," he tweeted.
"From Salisbury to the Middle East, why can he never bring himself to back British allies, British intelligence or British interests?"
In a statement, the Foreign Office said "no other state or non-state actor could plausibly have been responsible" for the incident.
It was broadly in line with the assessment of the United States which has firmly blamed Iran – a claim which Tehran denies.
Mr Corbyn tweeted: "Britain should act to ease tensions in the Gulf, not fuel a military escalation that began with US withdrawal from the Iran nuclear agreement.
"Without credible evidence about the tanker attacks, the government's rhetoric will only increase the threat of war."