Image caption Many banks already offer Welsh language services in response to customer demand

Supermarkets and banks could be forced to provide services in Welsh as part of a drive to boost use of the language, BBC Wales understands.

The Welsh Government wants there to be one million Welsh speakers by 2050.

Public bodies like councils already have to provide services in Welsh, with new standards being set for water, energy, bus and rail companies.

Campaigners have said Welsh language minister Alun Davies told them they should cover the whole private sector.

Assembly members were discussing the target of one million Welsh speakers in the Senedd on Wednesday.

The issue of compelling private companies and public bodies to offer services in Welsh has been controversial in some quarters on the grounds of cost and complexity.

The pressure group Cymdeithas yr Iaith Gymraeg (Welsh Language Society) has said Mr Davies told them of his support for widening such measures to other firms at a meeting in March.

In a letter to the minister the following day, the group said: "We are glad that you are privately and personally in favour of including the rest of the private sector in the measure."

The Welsh Government is expected to publish its plans to reform Welsh language requirements before the assembly breaks for summer recess in late July.

Plaid Cymru, which led the debate on Wednesday, is urging ministers to plan for "substantial growth" in Welsh medium education and childcare, strengthen the role of the Welsh language commissioner, and to ensure economic planning takes the Welsh language into account.

Consultation in 2016 on the target of one million Welsh speakers suggested it would be based on the census returns where people in Wales are asked to identify whether they speak the language or not, although not how fluently or regularly.

The last census in 2011 showed the number of Welsh speakers in Wales fell from 582,000 in 2001 (20.8% of the population) to 562,000 (19%).

The 1911 census reported the number of Welsh speakers as being close to a million at 977,000.