The British government has deployed troops to defend oil fields in Saudi Arabia without telling parliament or the public.

Opposition parties accused the government of lacking a "moral compass" and dodging scrutiny, while campaigners said the episode was "symptomatic of the toxic relationship" between the UK government and the oil-rich autocracy, The Independent reported. 

The Ministry of Defense says the oil fields are "critical economic infrastructure" and that gunners from the 16th Regiment Royal Artillery were needed to help defend against drone strikes.

Incredibly, the military operation, which was launched February in this year, overlapped with a ban on exporting military hardware to the Western Asian dictatorship.

Until July ministers were blocked by the Court of Appeal from signing-off military exports because of concerns that Saudi forces were committing war crimes in their conflict with rebels based in neighboring Yemen.

Legal action is ongoing in British courts to reinstate the ban, which ministers discarded in the summer after judging that the 500 alleged war amounted only to "possible" breaches international humanitarian law and "isolated incidents".

A Ministry of Defense spokesperson told The Independent: “Following the attacks on the Kingdom of Saudi Arabia’s oil production facilities on 14 September 2019, we have worked with the Saudi Ministry of Defense and wider international partners to consider how to strengthen the defense of its critical economic infrastructure from aerial threats."

The spokesperson confirmed that the deployment had included an advanced military radar system to help detect drone strikes, but would not be drawn on "exact timescales or the numbers of personnel involved due to operational security".

No response was provided to questions about why no announcement had been made in parliament or elsewhere about the deployment of British troops.

Defense minister James Heappey confirmed in separate written correspondence that "UK defense personnel have accompanied the deployment of Giraffe radars to Riyadh [the Saudi Arabian capital]".