A battle of wills has kept relations between Beijing and the Vatican poor for more than half a century. Both insist they have the right to determine how the Catholic religion is administered and by whom. The coming and passing of popes in Rome has had no effect; pressure from outside the mainland to allow more religious freedom has largely been ignored. Nor has the Vatican budged on demands from Beijing to drop its diplomatic recognition of Taiwan. But the appointment of a new bishop in Shanghai, apparently with the blessing of both sides, marks a small and highly welcome shift. It is an opportunity that can easily be capitalised upon to move aside issues that until now seemed intractable. Beijing severed ties with the Vatican in 1951 and ordered Catholics to worship in the government-sanctioned church, known as the Chinese Catholics Patriotic Association. Authorities say that 4 million do, but foreign experts claim another 12 million take part in the unofficial, or underground, church. Shanghai is not the centre of Catholicism on the mainland - the religion is more widely embraced in northern provinces. As the nation's biggest and most progressive city, though, what happens there could well be seen as a bellwether for change elsewhere. That may be part of the reason for Catholic leaders applauding the appointment of the foreign-trained Joseph Xing Wenzhi, 42, on Tuesday as an assistant, and apparently anointed successor, to Bishop Aloysius Jin Luxian , 89. But what caught most attention was Bishop Xing's announcement during the ceremony that he had been nominated by the Holy See. Although mainland officials have since said that he was chosen wholly by Chinese Catholics and authorities, his public statement of Vatican acceptance signals a subtle, but significant, shift. Bishop Jin foreshadowed the move last week by saying that the Vatican had indicated it would not recognise a successor to the leader of the underground church in Shanghai, Bishop Joseph Fan Zhongliang , who is in poor health. Days earlier, the Vatican's Foreign Ministry said establishing ties was possible, but would take 'goodwill and a spirit of friendship'. The Vatican in the past has apparently had a hand in choosing bishops on the mainland and they were ordained without objection, but amid pressure to keep the fact secret. The manner of Tuesday's announcement therefore represents a breakthrough. Such openness is a small and significant step towards the compromise that is necessary to improve relations. The statements of recent weeks are a far cry from the bad-tempered rhetoric of the past. These are positive signs and provide the impetus to kick-start the process of working towards normalisation.