Wimbledon Champion Pat Cash has said a number of women tennis players at the Wimbledon Championships have been told to play without their sports bras after the garments were judged to have fallen foul of the tournament's new, stricter guidance for on-court clothing.

The new rules, introduced by Wimbledon's organiser – the All England Club – shortly before this year’s event, aim to tighten the tournament’s “all white” dress code.

The rules have been brought in to clamp down on players wearing coloured, branded underwear – seen as a way for players’ sponsor companies to be able to promote themselves covertly without being an official partner of the tournament.

The practice - called ambush marketing - has a long history at major sports events.

One of the most high-profile cases in recent years took place at the Euro 2012 football tournament, when Danish player Nicklas Bendtner was fined €100,000 (£80,000) and banned for one competitive international fixture for displaying sponsored underwear – showing the name and logo of betting company Paddy Power – after scoring a goal during Denmark's game against Portugal.

A recent study by professors Michael Parent and Leyland Pitt – at US-based Beedie School of Business – shows that the effectiveness of ambush marketers can leave sponsors of major events particularly vulnerable, costing them not only their financial investment, but ultimately their customers.

Their study Event sponsorship and ambush marketing: Lessons from the Beijing Olympics shows that the increased efforts by "ambush marketeers" are leading to many companies being incorrectly identified as a official sponsors — and benefitting from the positive effects this has on measures of brand attitude and recommendation likelihood. To purchase and view the study, click here

While event organisers are within their rights to take measures against covert marketing, however, the decision by Wimbledon to tighten rules on undergarments has stirred up a strong reaction from players past and present.

Former Wimbledon champion Pat Cash criticised the rules, describing them as “ridiculous”.

Speaking on BBC5 Live, Cash said: “Some of the girls have been told to go back and change their bras and tops because they had slight colour on them. I believe some of the girls didn't have suitable sports bras and had to go without them. It has absolutely gone ridiculous."

Meanwhile, five-time Wimbledon champion Venus Williams tweeted that she planned to ignore the rule by wearing a colourful bra during her third round tie against Petra Kvitova – a game Williams lost in three sets (see below).

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Venus Williams tweeted her opposition to the new rules

Wimbledon stats:• The 2014 Wimbledon Championships will run until 6 July

• This year’s tournament is the 128th - the first one was held in 1877• The Wimbledon Championship is the world's oldest tennis tournament and remains the only Grand Slam event to be played on grass

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