This is the full text of Priti Patel's letter of resignation as International Development Secretary:

Dear Prime Minister,

It has been a tremendous privilege to serve in your Cabinet since you became Prime Minister in July 2016.

During my time as Secretary of State for International Development, I have been proud to work alongside you, colleagues in Government and our partners across the world to support the poorest and most vulnerable people in the world.

It has been a privilege to preside over a Department which has a team of remarkable individuals who often face adversity and danger in tough and challenging circumstances. Our teams across the world are displaying the ingenuity of the human spirit every single day as they strive to save lives and give vulnerable people new opportunities. I have seen at first-hand the refugee camps and the projects we support across the world. Seeing how the aid and support provided by this country is transforming and saving lives is truly remarkable. These are experiences that I will never forget and will forever inform my views and outlook on the world.

In humanitarian crises and natural disasters, along with volunteers and charities, the Department's staff are amongst the first on the ground courageously acting to save lives by providing food, medicines and shelter. The human decency, compassion and commitment they show is simply awe-inspiring and they are a credit to our county.

Our actions to reform the global aid system, invest in new projects that deliver better outcomes and support economic development will make a lasting positive difference to the poorest in the world.

I have seen the very best of Britain and know it will flourish on the world stage as we leave the European Union. We should all be very proud that across the world the Union Flag on our aid parcels and on the projects we support is seen as a symbol of hope. Our country is a force for good in the world and as Secretary of State for International Development it has always been my focus to act in the best interest of our great country.

In recent days there have been a number of reports about my actions and I am sorry that these have served as a distraction from the work of the Department for International Development and of the Government as a whole. As you know from our discussions I accept that in meeting with organisations and politicians during a private holiday in Israel my actions fell below the high standards that are expected of a Secretary of State.

While my actions were meant with the best of intentions, my actions also fell below the standards of transparency and openness that I have promoted and advocated.

I offer a fulsome apology to you and to the Government for what has happened and offer my resignation.

From the backbenches I will take an active role representing and speaking up for the good people of the Witham constituency. I look forward to highlighting the great entrepreneurial spirit in this part of Essex that has created new jobs and growth and to take my campaigns for new investment in infrastructure and services to the floor of the House of Commons.

I will continue to support you and the Government and stand up for the Conservative values of freedom, opportunity and aspiration.

I will also speak up for our country, our national interests and the great future that Britain has as a free, independent and sovereign nation.

I wish you and the Government all the very best.

With all good wishes,

The Rt Hon Priti Patel MP

READ MORE: Priti Patel resigns as International Development Secretary

This is the full text from Theresa May's response letter:

Dear Priti

Thank you for your letter following our meeting this evening confirming your resignation as Secretary of State for International Development.

As you know, the UK and Israel are close allies, and it is right that we should work closely together. But that must be done formally, and through official channels. That is why, when we met on Monday, I was glad to accept your apology and welcomed your clarification about your trip to Israel over the summer. Now that further details have come to light, it is right that you have decided to resign and adhere to the high standards of transparency and openness that you have advocated.

As you do so, you should take pride in what you have achieved as Secretary of State. You have ensured that the UK aid budget continues to deliver value for money for British taxpayers, in support of our national interest, while helping some of the world's most vulnerable people. The reforms to which you secured agreement at the High Level Meeting in Paris last week are just one recent example of this.

Under your leadership, the Department for International Development has increased its work on economic development, including on trade, helping developing countries to lift themselves out of poverty and creating the trading partners of the future. I also welcome your efforts on the global health agenda, notably as co-host of the Family Planning Summit in London this summer, and DFID' s work in leading the humanitarian response in the Overseas Territories affected by the recent hurricanes in the Caribbean, and responding to the refugee crisis in Burma and Bangladesh.

Through this work and more, you have helped to ensure that, as the UK leaves the EU, we build a truly Global Britain.

You rightly take pride in being the first British Indian Cabinet Minister - a significant achievement which follows your work as Exchequer Secretary to the Treasury and Minister of State for Employment, and your years of service to your constituents in Witham, whom I know you will continue to serve with great commitment and devotion.