An estimated 85,000 children have already died from extreme hunger and the charities say more than 14 million people are now facing starvation.
They say it is the worst humanitarian crisis in the world and are urging all parties to the conflict to put the country's people first.
Deborah Hyams, Humanitarian Policy and Advocacy Advisor for Christian Aid told Premier:
"This is not a natural disaster. This is happening because of the war and all the different parties that are contributing to that fighting and we're asking everyone, all the leaders of all the different countries involved to put people first."
Hopes were raised in December 2018 when a ceasefire was agreed between the Iranian backed-Houthi forces and the Saudi coalition in the port of Hodeida.
But Deborah Hyams told Premier that this has not yet brought the relief that was hoped.
"Neither the Houthi forces, nor the Saudi coalition have withdrawn their troops and agreed on those troops' withdrawals and how to implement that."
The charities welcomed the UK government's announcement last week that it will be increasing its funding to the UN Peace process in Yemen by £2.5 million, but said the situation is so desperate that much more needs to be done.
Christian Aid encourages those who would like to pray to be guided by the following prayer points:
For peace for the people of Yemen
For wisdom for those involved in diplomacy and a resolve to bring about an end to the conflict
For the religious authorities in all of the nations involved to speak truth to power
For the people of the UK to be stirred to act to raise awareness of the plight of those living in Yemen, men and women we believe are made in the image of God, just like us.
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