Savers who stay loyal to big banks are missing out on hundreds of pound of interest each year as they continue to hack at rates, research shows.

The biggest banks' standard easy-access rates now pay a pittance of just 1.19 per cent on average compared to 4.12 per cent on offer from the best buy savings accounts, according to Moneyfacts Compare.

That's the difference between earning £119 and £412 with a savings pot of £10,000 over the course of a year. 

It means savers who simply plump for the high street giants - often out of ease of sticking with where their current account is - are almost £300 worse off annually. 

Lloyds Bank offers the worst deal - a 0.75 per cent rate on its easy saver account. This amounts to just 75p for every £100 saved.

NatWest's flexible saver account pays 1 per cent, Barclay's everyday saver pays 1.05 per cent, HSBC's flexible saver pays 1.14 per cent and Santander's easy access saver pays 2 per cent.

The average easy access rate is currently 2.42 per cent, according to Moneyfacts. 

Last week the Bank of England opted to hold the base rate at 3.75 per cent. 

The base rate affects how much interest savers can earn on their money. In general, savings rates rise when the base rate is rising, and fall when it is falling.

Savings rates have been slipping from their peak for many months, and this is expected to continue. 

The easy-access rates on offer from big banks are a fraction of the 4.12 per cent average from top easy-access accounts from challenger banks. 

Caitlyn Eastell, of Moneyfacts Compare, says: 'With savings rates expected to drop further from the peaks seen over the past few years, staying in a low-paying account may amplify the cost, making it harder for savers to reach their financial goals. 

'Switching to a lesser-known challenger bank could help offset this, as they often offer more attractive rates.'

Shawbrook Bank is paying 4.13 per cent with a 2.13 per cent bonus rate included in this rate for 12 months. There are no restrictions on how often you can access your money.

While Spring, part of Paragon Bank pays a rate of 4.11 per cent and allows you to access your money at any time. This rate does not include a bonus rate. 

Ms Eastell says: 'Savers should remain alert. Challenger banks often lead the market with headline rates that include limited-time bonuses, sometimes exceeding 2 per cent.

'Once bonuses expire, rates can fall sharply, so passive savers risk being left behind and those seeking stability may find these less suitable for long-term planning.'