Uefa urged to end standing ban by football fans' groups
European fans' groups have backed a call for Uefa to end a ban on standing at continental games.
The English Football Supporters' Federation was among the signatories of an open letter to Uefa president Aleksander Ceferin.
It marks the start of a series of protests at European fixtures under the slogan 'Europe Wants to Stand'.
Tuesday's Champions League tie between Tottenham and Borussia Dortmund was the first to see protests.
The letter from the Football Supporters Europe network was also signed by groups from Wales, Northern Ireland and the Republic of Ireland.
"In the name of the majority of supporters across the continent, we urge you to reconsider this ban and give us the choice of whether to sit or stand at football matches," the letter read.
It described Uefa's all-seater policy, introduced in 1998, as a "quick solution" to several major incidents that took place in European stadiums, among them the 1989 Hillsborough disaster.
"A number of long-term evaluations have concluded that the existence of standing sections was not the cause of these tragedies," the letter added.
"The fact that it is possible to provide standing sections without safety or security risks at football matches is clearly evident in Germany, where approximately 100,000 fans stand up every weekend.
"At every Premier League and Championship game, thousands of fans stand in areas not specifically designed for standing.
"It is our belief that stadia must be open to people from all walks of life. The provision of tickets in standing areas is one of the easiest ways to achieve this objective."
Standing is permitted in Leagues One and Two, but not in English football's top two tiers after it was outlawed by the Football Spectators' Act in 1989.
That legislation followed recommendations made in the Taylor Report into the Hillsborough disaster. However, the policy is currently under review by the government.
In November, Wycombe became the first English club to give some fans the choice to stand or sit without blocking the view of others by installing 68 '2020 seats' at Adams Park.
Shrewsbury installed a different scheme at the start of this season with more than 500 rail seats introduced at the Montgomery Waters Meadow stadium - a similar concept to the one used by Celtic.
The Scottish champions opened a 2,900-capacity safe standing area at Celtic Park in 2016.