The biggest ever World Cup is almost here, with the United States, Canada and Mexico ready to host 48 teams in an expanded competition.The football finally begins on Thursday as Mexico host South Africa at Mexico City’s iconic Estadio Azteca.Recommended Stories list of 4 itemsend of listBut before a ball has even been kicked, the tournament has already thrown up plenty of controversy. Here are the five biggest talking points on the eve of the big kickoff.Iran’s tickets ‘withdrawn’ by the USThe Iranian football federation, FFIRI, says the US has revoked its allocation of tickets for its team’s World Cup group games, accusing the cohost of obstructing the attendance of Iranian supporters under the shadow of war.“In an unexpected move, the allocation granted to the Iranian Football Federation has been withdrawn, and under the current circumstances, the federation is unable to provide even a single ticket to supporters of the national team,” FFIRI said.The US has presented several bureaucratic hurdles for Iran at the World Cup, including refusing to issue visas for some of its support staff, as the two countries have effectively remained at war since the US-Israeli attacks on Iran on February 28.Neither FIFA nor US organisers have publicly commented on the Iranian accusation.Mexico City hit by protests before openerThe tournament kicks off in Mexico’s capital on Thursday afternoon, but various protests are putting pressure on the authorities in the run-up to the big game.Demonstrators from the country’s teachers’ union, CNTE, have been protesting in Mexico City for days and are threatening to shut down roads around the venue, Estadio Azteca, before the opening game. Adv …