Lewis Hamilton has described his ongoing contract issues as 'a pain in the backside' as the reigning Formula One world champion has become mired in paperwork. Following the Malaysian Grand Prix 11 days ago Hamilton claimed his new deal with Mercedes, worth an estimated £21million per year, was '99.6 per cent done' and was now in the hands of his lawyers. But the fine print of the terms and conditions means the 30-year-old, who opted on this occasion - and for the first time in his career - to negotiate for himself without an agent, is becoming frustrated. Lewis Hamilton, who leads the world championship after two races, is pictured in the Shanghai paddock . The British sporting star was sporting two gold chains ahead of this week's Chinese Grand Prix . Lewis Hamilton, pictured at a Hugo Boss promotional event, says his Mercedes contract has not been sorted . The British world champion admits issues with paperwork has been 'a pain in the backside' According to Hamilton it now means 'it is unlikely' the contract will be signed ahead of this weekend's Chinese Grand Prix. Speaking to Sky Sports News, Hamilton added: 'Obviously at the last race I said it would be done within a week. 'This is my first time negotiating myself and you don't know how many times I've had to read about 80 pages. 'It is so much reading and it is all in lawyer jargon, so it has been quite a pain in the backside to be honest.' Despite the issues with the new deal, Hamilton is favourite to return to the top step of the podium on Sunday at the Shanghai International Circuit. Hamilton is a three-time winner at the venue - including last year - whilst he has finished in the top three on three other occasions. Hamilton is surrounded by the media at the Hugo Boss event in Shanghai on Wednesday . Mercedes driver Hamilton and team-mate Nico Rosberg (right) were beaten by Sebastian Vettel in Malaysia . Despite Ferrari winning their first race for almost two years last time out in Malaysia, with Sebastian Vettel at the wheel, the much cooler conditions in China should play into Mercedes' hands. 'Malaysia was a tough weekend,' said Hamilton. 'It always is with the heat, but with car problems on Friday, rain during qualifying on Saturday and a race which didn't go to plan on Sunday, that one was particularly challenging. 'Ultimately we made the best choices we could, but there is always room for improvement and we've been working hard to analyse everything for this next race in China. 'The circuit is one I really enjoy and it suits my driving style quite well. 'I won the race last year and have only finished outside of the podium places twice, so the target is definitely to build on that and get back to the front.' Hamilton, pictured driving during final practice in Malaysia, says the last Grand Prix was a 'tough weekend' He won last year in China and will be hoping for more joy in Shanghai this weekend .
Lewis Hamilton said at Malaysian Grand Prix that contract was nearly done .
British world champion is negotiating contract without an agent .
Hamilton admits it is unlikely Mercedes deal will be agreed this weekend .
Driver is preparing for Shanghai Grand Prix in China .