Welsh Secretary Alun Cairns has resigned following claims he knew about a former aide's role in the "sabotage" of a rape trial.
Here is his resignation letter and the prime minister's response in full.
Alun Cairns wrote:
Dear Prime Minister
You will be aware of allegations relating to the actions of a party employee and candidate for the Welsh assembly elections in the Vale of Glamorgan.
This is a very sensitive matter, and in light of continued speculation, I write to tender my resignation as secretary of state for Wales.
I will cooperate in full with the investigation under the Ministerial Code which will now take place and I am confident I will be cleared of any breach or wrong doing.
It has been an honour to serve in your government and a privilege to see the positive steps you have made in such a short time. Your work to secure a deal to leave the European Union has been extraordinary and the opportunities it brings are exciting for all parts of the country. I thank you for your commitment to the Union and the way in which you have made it central to all areas of government policy.
My experience of seeing your work first hand with Cabinet colleagues gives me confidence for the future. Your vision and drive to move the country forward to meet the opportunities of Brexit and to protect and enhance public services is exemplary.
I will continue to work to support your vision and ambitions for the country and am grateful for the honour of serving in your Cabinet.
Rt Hon Alun Cairns MP
Secretary of State for Wales
The Prime Minister Boris Johnson replied:
Thank you for your letter resigning as secretary of state of Wales. I am pleased to hear that you will co-operate fully with the Cabinet Office during this process.
I am extremely grateful for all the work you have done in the role as secretary of state since March 2016. In particular, I would like to put on record my gratitude for all the support you have given to this government in ensuring we honour the commitment to the people that we leave the European Union. Given your long service as secretary of state, you can be proud of your record of delivery for the people of Wales, in particular in ensuring the abolition of tolls on the Severn bridges.
This an unstinting record of service to the party in Wales with over a decade as assembly member for South Wales West where you were a vocal critic of the Labour government.