Agent Marcelo Lombilla has been infuriated by the Galician club's stance over a bid from the Premier League outfit after they raised their asking price once an offer had been made.
According to the Argentinian's representative, Depor wanted 12million euros (£9.5m) and he informed Newcastle, who then lodged a bid of that amount only for the valuation to rise to 14million euros (£11m).
"(Depor president Augusto) Lendoiro needs to come and say what he means. One day he says a million will be enough, but you know that means a million and a half, for sure," Lombilla told AS.
"For Coloccini it is awful that he may miss out on the contract of his life."
If no deal can be reached in the next few days, then Lombilla believes that the player will be left with no choice but to invoke Article 17 of FIFA's regulations and walk out.
"We do not want to do that, but they are pushing us very close to the edge," the agent added.