Wales is still set to lose around eight of its MPs despite plans to make the House of Commons smaller being dropped.
The total number of MPs was to fall from 650 to 600, with Wales having 31 rather than the current 40 MPs.
Now UK ministers say they want to keep the current number of MPs, due to "a greater workload" following Brexit.
Ministers are pressing ahead with creating constituencies with a near-equal numbers of voters, leaving Wales with around 32 seats, it is estimated.
David Cameron had proposed the original idea to shrink the Commons in 2012, when he was prime minister, to reduce the cost of politics.
But there was considerable opposition to the plans, with one Welsh Conservative MP who has since left Parliament calling them "anti-democratic".
Cabinet Office minister Chloe Smith said in a written statement that following the UK's departure from the EU Parliament will be taking on more work and, therefore, a reduction in the number of MPs was no longer needed.
Equalising the numbers of voters in constituencies will still lead to a significant redrawing of the electoral map and see some safe seats transformed into marginals, and vice versa, throughout the UK.
Ministers will also call for constituency boundary reviews to take place every eight years instead of every five.
The Boundary Commission will be asked to draw up a new map of constituencies in a review that is due to begin in early 2021.