The rate is the lowest average seen since October last year (when it also stood at 1.42%). The drop is also the largest month-on-month decrease since September 2016.

Moneyfacts found that not only are one-year fixed bond returns decreasing, but longer-term fixed rates are also falling, with April the first time both averages have dropped within the same month since January 2017.

Meanwhile, the shelf life of fixed rate bonds overall has dropped to an average of 48 days, the shortest period seen since January 2017.

Moneyfacts finance expert Rachel Springall said: “It seems likely that economic uncertainties are starting to impact the attitude of savers, as the demand for tying up their cash wanes. The Bank of England estimated £3bn flowed into instant accounts during February, while separate figures from UK Finance revealed deposits into accounts that require a tie-in fell by 5.6% year-on-year.

“This latest shift in the market will come as disappointing news to savers hoping for the market to recover at a faster pace. The drop since last month is in stark contrast to the start of 2019, where the average one-year fixed bond rate had risen consecutively – from 1.43% in January to 1.47% in March – thanks in part to the determination of challenger banks to attract new money to fund their future lending.

“Savings providers offering a fixed rate bond commit to the interest they pay for the duration of the term, so it’s no surprise that they must adapt their market position should they attract too many deposits. Therefore, this fall may well be the start of providers’ attempts to sustain their offerings or reduce the cash coming in by making reductions or withdrawals – but this could drive others to follow suit as they unexpectedly climb the rate tables.”

The top-paying one-year fixed rate bonds are currently offered by Islamic Banks operating to Shariah principles and offering an “expected profit rate” instead of an interest rate. BLME pays 2.2%, Al Rayan Bank 2.17% and QIB UK 2.05%.