NatWest has become the latest major lender to announce increases to its fixed mortgage rates, following similar moves by Barclays, Nationwide, Coventry Building Society and Virgin Money as heightened geopolitical tensions feed through into wholesale funding costs.

NatWest will increase selected fixed mortgage rates by up to 0.27% from Friday 17 July, adding to a series of repricing announcements across the market over recent days.

The latest changes come after renewed tensions in the Middle East unsettled financial markets, prompting a rise in swap rates that underpin the pricing of fixed-rate mortgages. Lenders have responded by withdrawing cheaper products and introducing higher rates.

While many of the increases announced so far have been relatively modest, some have been more significant. Nationwide, for example, recently increased its market-leading two-year fixed purchase rate from 4.24% to 4.59% – a rise of 0.35% which equates to almost £40 a month, or around £480 a year, in additional repayments for some borrowers.

David Hollingworth, associate director at L&C Mortgages, said: “The story for mortgage rates in recent weeks has generally been positive, as cuts to fixed rates have dragged the market in a positive direction.

“However, any borrower hoping for rate cuts to become an ongoing trend will need to rethink, as a growing number of lenders have announced impending hikes to fixed deals in the coming days.

“The resumption of hostility in the Middle East has caused further uncertainty in financial markets, as the threat of higher interest rates returns. That’s affecting lenders’ funding costs and has already resulted in several major lenders announcing that they have increased fixed rates or are about to.

“Several moves in quick succession is usually a signal that others will not be far behind. Borrowers that had been holding on in the hope of further reductions improving their rate choice may now need to hurry if they want to avoid missing out on some of the lowest rates.

“Although many increases have so far been slight, others are chunkier. For example, Nationwide’s leading two-year fixed rate for purchases at 4.24% has now lifted to 4.59%, an increase of 0.35% equating to an uplift in monthly payments of almost £40pm or £480 per annum.

“Things can change quickly but securing a rate now could avoid being hit with further rises while still allowing a further review of rates before completion if the situation eases back again.”