Ipswich Town chief executive Mark Ashton insists that the club's summer spending spree is not over.

The Blues have signed five players since securing promotion to the Premier League in the form of attacker Omari Hutchinson, striker Liam Delap, centre-back Jacob Greaves, goalkeeper Arijanet Muric and right-back Ben Johnson.

Those deals cost a combined £56m in transfer fees and have the potential to reach £70m if all add-ons are hit. With a centre-midfielder, left-sided attacker and striker all still understood to be on the shopping list, the Blues' outlay could end up being close to £100m.

"It's a tough window," Ashton told TownTV. "We're swimming in a bigger pond than we've ever swum in before. It's the same challenges, just with different numbers - much bigger numbers. And when you’re dealing with much bigger numbers, your room for error is far less.

"I think what you've seen with myself and (manager) Kieran (McKenna) is that we've stuck to the plan. Kieran's been very clear and very diligent in the work that he's being doing. Some very talented people have come into the building, who will grow with us.

"Five in, and that’s not the end of it. Fans will understand we are proactive in transfer windows. I think we’ve done decent business in previous windows in other leagues and I think we’ll continue and you’ll see more players over the next few weeks arrive ahead of the season."

On how he's found operating in the Premier League market, he added: "It's as tough as I expected. Negotiations are probably tougher than ever because you've got to get value.

"It's very easy to overpay and if you overpay on the way in, in a deal, the deal's never right and you're struggling from day one.

"The due diligence we do on the type of player, the personality, the finances, the technical, the tactical piece from Kieran all has to come together.

"Myself and Kieran lead on that, while (chief operating officer) Luke Werhun has been absolutely invaluable in the work he's done behind the scenes. He's certainly got more grey hairs this summer.

"It's relentless, but that's what we do. We don't sing and dance, we don't talk into the media what we're doing. I think the fans have been great, I think they’ve been really controlled in the way they've talked about who we’re looking to bring in, which has helped us again. And we'll keep going, there's more to do."

Town's pre-season preparations continue with a friendly against German club Fortuna Dusseldorf, at Portman Road, tomorrow afternoon (3pm).