Referees will now be able to take action against doctors and physios on the bench. Jeff Gross/Getty Images

Referees at the European Under-21 Championship have been given the power to show yellow and red cards to non-coaching staff in the technical area as part of a "Play Fair" initiative, UEFA has announced.

The International Football Association Board (IFAB), the body that oversees all the sport's laws, has sanctioned changes proposed by UEFA's Executive Committee earlier this month that will mean referees can show yellow and red cards to physios and team doctors in addition to coaches and substitutes.

The distribution of cards for non-playing staff aims to clarify when a player or official is officially cautioned or dismissed from the technical area.

Those displaying a clear lack of respect for match officials, such as sarcastic clapping, or committing acts such as kicking water bottles or asking for a yellow or red card to be shown could receive a booking.

�� TODAY'S THE DAY! ��

The #U21EURO kicks off in Poland! Who will shine this year? Match calendar �� https://t.co/R9IXZ6DVIj pic.twitter.com/fZeg5ZEBdk - UEFA U21 EURO (@UEFAUnder21) June 16, 2017

The use of offensive, insulting or abusive language, displaying physical or aggressive behaviour towards a member of the opposition team or a match official, or confronting a match official on the field of play are among the actions that could lead to a red card for non-playing staff.

A fourth substitution in extra time, which has also been used in some domestic cup competitions recently, will also be trialled.

Using the results of a limited pre-study survey by FIFPro, which took into account the opinions of players, coaches, administrators and medical staff, the IFAB decided to sanction the change with nearly 85 percent of those consulted in favour.

The trials will also be conducted at three other tournaments this summer: the Women's European Championship in the Netherlands, the European Under-19 Championship in Georgia and the European Women's Under-19 Championship, which is taking place in Northern Ireland.

The tournament gets underway in Poland on Friday with Sweden taking on England.