Planners for the tournament, which for the first time is to be held in 13 countries across Europe instead of in one or two countries, want the three matches at the climax to be held in a single stadium.
Wembley has a strong chance - but if Istanbul fails to win its 2020 Olympic bid then it would be viewed as the favourite. UEFA sources say Berlin, Madrid and Rome are also weighing up bids.
The tournament planners have recommended that Euro 2020 venues must be served by an airport with at least two terminals to keep rival fans apart - meaning that Cardiff's Millennium Stadium would face a struggle to be chosen as one of the 13 cities.
The Welsh FA would have to argue that Bristol or even airports further afield could be used as an alternative for fans.
Dublin and Glasgow are also expected to bid to host group matches at Euro 2020 but do not have the same issue with airports.
The Football Association will also bid for group matches and quarter-finals if its final bid is unsuccessful.
Two cities with smaller-capacity stadiums will be among the 13 chosen in an effort to broaden the reach of the tournament. Two host cities can have a stadium capacity as low as 30,000, 10 stadiums will have a 50,000 minimum capacity and those hosting the quarter-finals will have grounds holding at least 60,000.
The stadium that hosts the two semi-finals and final will have to be able to seat more than 70,000 fans.
UEFA's executive committee is expected to agree to the plans at its meeting on March 28.
The idea in having two 30,000-seater stadiums means smaller countries will be able to enter the bidding - only 21 of the 53 UEFA member nations have stadiums of 50,000 or more.
Planners believe that host countries will be able to play at least two of their group matches at home.
Meanwhile, Britain's historic FIFA vice-presidency is set to be saved from threatened extinction after European countries unanimously decided to back moves to retain the post.
The 53 UEFA countries would elect the British representative themselves, however, rather than merely accept the nomination of the four home nations.
The new policy was agreed as part of UEFA associations' proposals for FIFA reforms, under which they will also propose that from 2015 the FIFA president will serve an eight-year first term and then be permitted a second four-year term, mirroring the International Olympic Committee.
The European countries also decided at a meeting today to propose an age limit of 72 for elections to the FIFA presidency and executive committee.
The British FIFA vice-presidency has existed since 1946 with the idea it is shared between the four home nations - the current incumbent is Northern Ireland's Jim Boyce.
UEFA general secretary Gianni Infantino said there was widespread support for the British position being maintained.
He said: "The move of the four British associations to propose that all 53 UEFA associations elect the British vice-president has certainly helped in this respect as it brings the British closer to the centre of European football."