Hampden Park has been the official national stadium of Scottish football since 1906

There is a realistic chance that the Scottish Football Association could leave Hampden Park, says chief executive Stewart Regan.

The governing body is in discussions with Rangers, Celtic and Scottish Rugby about switching internationals and cup finals, and the SFA board will discuss the matter next month.

The SFA's 20-year lease expires in 2020, but there is a renewal option.

"We're exploring the plusses and minuses of going," Regan said.

The SFA chief executive says it would cost "many, many millions of pounds" to stay at Hampden, requiring external funding from public and private bodies.

In addition to exploring the financial pros and cons of staying at Hampden or leaving, the SFA is also canvassing opinion from clubs, managers, the players' union and supporters groups.

The renewal option would allow the SFA to secure another 20 years at the national stadium, which is owned by Scottish League One club Queen's Park, and runs until the spring of next year.

Regan says the governing body is exploring all options as the Hampden renewal date looms

"The go option will involve exploring Celtic Park and Ibrox, both fantastic stadia where we've played matches in recent times against the Republic or Ireland and Georgia, and of course Murrayfield, where we've seen Hearts hosting their home matches in recent times," Regan said.

"Those are the three stadia capable of holding qualifiers because we have had an average attendance of over 31,000 for our qualifiers over the last 10 years, so those are the only stadia capable of satisfying that type of demand.

"For smaller qualifiers we would consider coming round the country to other stadia like Easter Road, Tynecastle and Pittodrie.

"But we need to do the numbers, we need to understand the costs of staying and the costs of going.

"All of that work is being done at the moment. We have a consultant helping us prepare business cases on either side, we'll discuss that in December and hopefully the board can then decide what the position is after that.

"In the early part of 2018 we need to be in a position to make a call one way or another."

Scotland international football matches have been played at Hampden since 1906, and it has officially been the national stadium since 1925.

As well as international matches, Scottish Cup and League Cup semi-finals and finals have been held there apart from times when the stadium has been under redevelopment.

Aberdeen's Pittodrie hosted Scotland's 1-0 friendly defeat by Netherlands on Thursday and Easter Road was the venue for a March friendly draw with Canada.

'It will come down to costing and funding'

Three group stage matches and one round-of-16 match at the Euro 2020 finals will be held at Hampden, and they could prove to be the last internationals played at the stadium.

"We know it will cost many, many millions of pounds to stay for another term of a lease similar to what we have now and we need to know that we can afford to stay if that's the option the board goes down," Regan added.

"We need to understand now how we can afford to stay and if we can't afford it then clearly we'd be negotiating a position with other partners.

"We've gone out to those four partners, Queens Park, the SRU, Celtic and Rangers in the last few weeks and we've received proposal requests back from them and are in dialogue. We'll complete that by December in order for the board to review the facts and figures.

"It'll ultimately come down to costing and funding. In order to run a national stadium you need to be able to maintain it, repair it and operate it, so all those factors will feature in our analysis."