"Even with a very large group of Polish priests, it isn't possible to reach in a timely way every place where Poles are found," said the Warsaw-based bishops' conference.

"Your witness of faith will positively influence believers from other national groups, especially those belonging to local church communities. Bishops in other countries count on such help from Polish Catholics."

In a pastoral letter to be read at Polish Masses abroad April 29, the bishops thank the 2,000 Polish priests and nuns currently ministering to Poles worldwide, and laypeople assisting with liturgical, educational, cultural and charitable work.

They thanked local bishops who had shown "openness and understanding" by making places of worship available and ensuring conditions for Polish-language pastoral work, but said Poles should now also attend Mass in the language of their country of residence.

"A mature patriotism has nothing to do with nationalism or closing off from other cultures and traditions – nor with today's increasingly fashionable internationalism, blurring the difference between particular nations," said the letter, marking the centenary of Poland's 1918 independence.

"Recognizing the unity of faith and your responsibility for the church, you should now make efforts to maintain good, regular contacts with Catholics of other nationalities. ... Promote Polish culture, defend Poland's good name, and maintain personal and institutional contact with the homeland. But also respect the country which has accepted you and given you work."

The Polish church runs missions or pastoral networks in 25 countries, by agreement with local bishops' conferences, catering for the religious needs of around 15 million Poles whose families left after World War II, the early 1980s Solidarity movement and Poland's 2004 accession to the European Union.

In France and Germany, where Polish missions have operated since the 1830s, 236 Polish priests currently minister to a combined Polish population of 3 million, while in the U.S., Polish clergy work at over 300 parishes.

In a January 2007 pastoral letter, the Warsaw bishops' conference said Polish parishes and missions were often "the only centers for Polish identity and culture" and urged Poles to seek out their own priests when abroad.

However, in August 2016, Archbishop Wojciech Polak of Gniezno told Catholic News Service Polish priests contracted to foreign dioceses often had trouble understanding local conditions, while a current decline in vocations would limit clergy available for mission work.

The Polish church's delegate for Catholics abroad, Auxiliary Bishop Wieslaw Lechowicz of Tarnow, told CNS April 26 that the 2007 pastoral had reflected the needs of a "very large number" of Poles who had left after their country's EU accession. He said many faced language and adaptation problems best tackled "in a climate of faith and tradition brought from the homeland."

However, he added that the situation had now improved, removing "barriers impeding contact with local church representatives and communities."

"It's important next-generation Polish emigrants not only know the Gospel and church teaching well, but also experience the faith not just in Polish-language communities – they mustn't associate the church only with Polish communities," Bishop Lechowicz said.

The bishop said Polish church leaders were aware Polish parishes came under a diocesan bishop's jurisdiction, adding that forms of contact and cooperation were carefully defined.

New Polish church guidelines are expected to outline priorities for Polish clergy abroad, to prevent disputes over jurisdictional issues and access to local churches, as well as over the separate practices of some Polish communities.

However, the rector of the Polish Catholic Mission in England and Wales, Msgr. Stefan Wylezek, told CNS April 25 that many Poles found English-language Masses cold, compared to their own "expressive, devotional piety."

He added that the church's canon law allowed Catholics to pray and worship in their own language and said full integration would "take one or two generations."

"There are no foreigners in the church – we are all one and, for me, mixed parishes offer the best hope," said Msgr. Wylezek, whose London-based mission has 217 parishes and pastoral centers, with 120 Polish priests.

"But we can't order this by decree; we have to devote time and effort to organizing and building our church communities, with all our cultures and backgrounds, so people can grow in faith."