No formal representations with respect to non-compliance with the Nuclear Non-Proliferation Treaty (NPT) have been made directly to the UK by another state party to the treaty.
Issues of non-compliance with nuclear safeguards agreements are dealt with by the International Atomic Energy Agency (IAEA) in Vienna. During the 37 years since the NPT came into force there have been many discussions by the IAEA Board of Governors on potential cases of non-compliance with safeguards. Recent discussions have centred on Iran and the Democratic People's Republic of Korea. The IAEA Board of Governors found Iran in non-compliance with its NPT-required safeguards agreement on 24 September 2005. The board expressed concerns about Iran's many failures and breaches of its obligations to comply with its safeguards agreement, and its history of concealment of nuclear activities. The board urged Iran to implement transparency measures, to suspend enrichment-related activity, to reconsider construction of a heavy water research reactor, and to ratify and implement the additional protocol. Iran has yet to comply fully with these measures, and was referred to the UN Security Council for further consideration in March 2006. UN Security Council Resolutions 1696 and 1737 set out the international community's requirements for Iran build confidence in the peaceful nature of its nuclear programme.
The UK has never been accused of non-compliance with its safeguards agreements with the agency or with its NPT obligations.