The fall in the value of the pound has prompted fears that interest rates in the UK could double by next year.
It comes after international markets reacted badly to UK Government plans to slash taxes for the highest earners and allow bankers to claim unlimited bonuses.
Kwasi Kwarteng, the new Tory Chancellor, claims the moves will help grow the economy - despite predictions the UK could already be in recession.
Higher interest rates means the cost of borrowing becomes more expensive. The biggest loan most Scots have is a mortgage - and the cost of that could soon jump.
Kirsty Blackman, SNP work and pensions spokeswoman, said: "People who have got their first mortgage since March 2009 have never seen BoE base rates above 0.75 per cent.
"Many have not planned for or predicted a massive hike because it hasn’t happened in so long."
She added: "Mortgage costs are set to go up more a month than Chancellor’s tax cuts will save most people annually."
What will the Bank of England do?
Interest rates are set by the Bank of England (BoE) and the markets are eagerly waiting to see its next move.
The bank said on Monday it would "not hesitate" to hike interest rates after the pound hit record lows.
It has already lifted interest rates seven times in a row since December to the highest rate in 14 years.
The central bank's next meeting is scheduled for November 3.
How bad could it get?
Samuel Tombs, chief UK economist at Pantheon Macroeconomics, said: "If mortgage rates rise to six per cent – as implied by markets' current expectations for Bank Rate – the average household refinancing a two-year fixed rate mortgage in the first half of 2023 will see monthly repayments jump to £1,490, from £863.
"Many simply won't be able to afford this."
A two-year fixed rate mortgage is the shortest-term offered in the UK for a fixed home loan.
Why does the value of the pound matter?
The UK Government plan to cut taxes for the richest is funded on borrowing. Investors are concerned about the country's ability to meet that debt led to the value of the pound being pushed down.
A weaker pound also makes imports and goods priced in dollars, such as oil, much more costly and risks fuelling price rises at a time when UK inflation is at its highest for 40 years.
