Arsène Wenger has spoken of his fear that Arsenal are being left behind by a financially elite cartel led by Barcelona and Real Madrid. Arsenal's manager also name-checked Chelsea and Manchester City as part of a group of clubs whose spending power has separated them from the rest of Europe's sides.

Arsenal start their Champions League group stage campaign at the German champions, Borussia Dortmund, on Tuesday night, and Wenger – in measured and realistic mood – accepted that his club are among those being forced to play catchup. The Frenchman foresees an economic meltdown across Europe and he said that it may be the only thing to rein in Barcelona and Real, who have benefited greatly from being able to negotiate individual television rights contracts in Spain. The Premier League has always had a collective agreement.

"I believe that this season, I see two teams that are above the rest – Real Madrid and Barcelona – and the rest have to catch up during the season," Wenger said. "So for us, it's a new start because we are a new squad. What is at stake during the group stage for us is to show that we can go through.

"We are in our 14th season in the Champions League group phase and what has changed is that the competition inside England has become bigger among the top teams.

"It is as difficult to win the Champions League because a team that wins the Premier League is in the Champions League final almost every year.

"Outside the country, Barça and Real Madrid have much more financial power than they had 14 years ago because they have individualised their TV rights. So they, at the moment, with teams like Man City and Chelsea can take who they want."

Wenger was asked directly about the emergence of a clutch of clubs with financial might that outstrips the rest, and the attendant difficulties for a club such as Arsenal. "You know about it, I don't need to explain that," he replied. "We have seen the first signs of some resistance in Spain, where everybody complains.

"I believe that Europe overall, as a unit, is going towards a massive crisis, which nobody really expects now. I am convinced that Europe will go into a huge financial crisis within the next three weeks or three months and maybe that will put everything into perspective again.

"Football is not untouchable. We live with people going to the stadiums as well and from advertising from people who buy products. All our income could be a little bit under threat in the next few months. Football is not only about money. We believe in ourselves that we can compete with them but it's as simple as this."

Wenger's mood took in the acceptance that Arsenal would enter the Champions League as only an outside bet to win it and fill the one significant gap on his CV. He has said that the club endured the summer from "hell" and only now does it seem that they are in the throes of an escape. The 1-0 Premier League win over Swansea City represented the start of the process and a big relief.

"We are full of hope but I understand why people raise that question [about Arsenal not being equipped to win the Champions League]," said Wenger, whose team came through a play-off tie against Udinese to reach the group stage. "We have not had a particularly strong start in the league. We have had five players coming in [just before the transfer deadline] and nobody knows how good they will be.

"I wouldn't rule it out but it's too early to speak about winning it [the Champions League]. Saying that would raise a lot of scepticism about the team and I don't think anyone would believe it. But we have to do as well as we can and we have to form a team in the next two months. It's too early to have that kind of ambition."