LISBON, Oct 22 (Reuters) - Already at war with the three companies that dominate Portugal"s mobile phone market, national regulator ANACOM is coming under fire from the government over a 5G auction that has been dragging on for months with no end in sight. Delayed by the COVID-19 pandemic, the auction of several spectrum lots was eventually launched by ANACOM in January, despite legal challenges from major players who say the rules unfairly favour new entrants. The regulator allowed operators to raise their bids by just 1% above rival offers, creating a drawn-out process of incremental increases. Recognising a "very slow evolution," ANACOM on Sept. 27 changed the rule to require a minimum increase of 3% to speed up the process. Prime Minister Antonio Costa has blamed ANACOM for causing a "huge delay" to Portugal"s 5G progress. "We all agree the auction model that ANACOM has invented is obviously the worst possible," Costa told Parliament on Wednesday.Anacom did not respond to an email request for comment on the prime minister"s comments. A spokesperson for Portuguese telecoms firm NOS (NOS.LS) said in an email the comments showed "the regulator"s profound incompetence" and called on its president to resign. Altice Portugal, another local operator, said by email it was time to take political decisions to favour economic development. Portugal and Lithuania are the only two European Union countries that have not yet embarked on a commercial rollout of 5G technology, which will allow for everything from self-driving cars to remote surgery. NOS, Vodafone (VOD.L) and Altice - which together serve nearly all of Portugal"s mobile customers - have taken ANACOM to a Lisbon court for reserving a portion of the spectrum for new entrants. They also complain at having to share infrastructure and offer national roaming to the new entrants" customers. Joao Confraria, a regulatory professor at Lisbon"s Catholic University and former ANACOM board member, criticised the regulator"s decision to determine the rules behind closed doors. "I hope this auction ends quickly, but we can apply the Portuguese saying: "what is born crooked may never grow straight"."