British ministers are expected to face difficult questions about the decision to seize an Iranian oil tanker two weeks ago, without guaranteeing that it will protect British-owned shipping in the Strait of Hormuz.
Iran has seized two oil tankers – one registered in the United Kingdom, the other in Liberia, but owned by a company with offices in Glasgow – Friday in the strait, which is the busiest oil route in the world, transporting up to 17 million barrels of crude oil per day.
Iranian forces released the Liberian flag ship, the Mesdar, after a couple of hours, but were still waiting for the Stena Empire on Friday night. Tehran is currently calling for the release of the Iranian oil tanker, Grace 1, which was arrested by British forces two weeks ago off the coast of Gibraltar.
Although there are no Iranian citizens detained on Grace 1, and no British citizen on Stena Empire, critics have already questioned whether the UK has dealt with Iran knowing that the Gulf waterways were not properly guarded.
Lord West, former head of the Royal Navy, said the UK should not "pretend to be surprised" by the Stena Empire incident. He told Sky News: "What I find extraordinary is that we knew that the Iranians would try something like this a few days ago.
"I am absolutely stunned by the fact that we did not implement a sort of control of the red ensign expedition in the region where no tanker would enter what is clearly a dangerous area without an escort, and I find it strange that we seem to have ships that do exactly that."
According to West, the British navy had "too few ships" and would find it "extremely difficult" to supply merchant ships.
Between 15 and 30 tankers flying the British flag cross the strait every day. In the region there are seven ships of the Royal Navy, accompanied by Royal Marines, for the protection of forces in the Gulf. The British presence includes a Type 23 frigate, HMS Montrose, which should be joined and then replaced by a Type 45, HMS Duncan.
In addition, there are four mine countermeasure ships – HMS Ledbury, HMS Blyth, HMS Brocklesby and HMS Shoreham – and a docking helper, RFA Cardigan Bay. HMS Kent will be replaced by HMS Duncan during the year.