Newcastle United have signed a four-year sponsorship deal with the payday loans company Wonga, a move that has been attacked by a trade body for insolvency professionals.

R3 claims that the fact that the north-east has the highest rate of insolvency in the country makes Wonga – which offers short-term loans at an annual percentage rate 4,214% – an inappropriate choice of sponsor.

Wonga's logo will appear on Newcastle shirts for next season and has agreed to invest £1.5m into supporting the club's academy and the Newcastle United Foundation Enterprise Scheme, which helps 15- to 16-year-olds find work.

The deal, which is worth £24m over the four years, also includes the naming rights of the stadium, but in a move that is likely to soften antagonism to Wonga, the ground will revert being known as St James' Park, having spent a year as the Sports Direct Arena.

But R3's president, Lee Manning, believes the deal has the capacity to do more harm than good.

"According to official figures, the north east has the highest personal insolvency rate of anywhere in the country, at 35.2 per 10,000 adults. This is compared to a rate of 29.6 in the North West and 17.5 in London.

"Wonga has chosen to target a region that has comparatively high numbers of people experiencing financial difficulty. Our experience tells us that many of those seeking high cost credit need professional advice for their financial problems, rather than accruing further debt."

There was also political opposition to the move. Nick Forbes, leader of Newcastle city council, said the deal represented a profit at any price culture at the club and warned of the possible social consequences.

He said: "I'm appalled and sickened that they would sign a deal with a legal loan shark. We see the devastating consequences of people getting into financial difficulty and we spend a lot of money each year helping people who are in debt through companies like this.

"It's a sad indictment of the profit at any price culture at Newcastle United.

"We are fighting hard to tackle legal and illegal loan sharking and having a company like this right across the city on every football shirt that's sold undermines all our work."

"It sets the tone for the city and I don't want this to be a city built on an image of cheap and irresponsible debt."

Ian Lavery, MP for Wansbeck, is a season ticket holder at the club but has said he will now not set foot in the stadium.

He said: "A city like Newcastle and the region should not have any ties with an organisation like Wonga.

"This business makes profits off the back of deprived people who are desperate and who are the most vulnerable in society. It's an absolute outrage and I now won't set foot into the stadium."

Chi Onwurah, MP for Newcastle Central, tweeted: "Some of the richest young men in Newcastle to wear shirts calling on the poorest to go to a legal loan shark."

Derek Llambias, the managing director of Newcastle United, said: "We are building a club that can regularly compete for top honours at the highest level. Throughout our discussions Wonga's desire to help us invest in our young playing talent, the local community and new fan initiatives really impressed us and stood them apart from other candidates."