Former Australian ExxonMobil workers were banned from attending the US oil giant's shareholder meeting in Dallas, Texas despite having proxies to attend from a Benedictine nun and a charity group.

The workers travelled to Dallas this week with the support of the Electrical Trades Union, Australian Manufacturing Workers Union and the Australian Workers Union as part of an ongoing industrial campaign against the company.

But ExxonMobil wrote to Sister Patricia Kirk from the Benedictine Sisters of Baltimore and the Needmor Fund in Ohio last week to say that Troy Carter from the Australian Manufacturing Workers Union had been "formally banned from attending or accessing any premises occupied by ExxonMobil".

Mr Carter said he was angry Exxon banned him and other former workers from the meeting, even though they travelled 14,500 kilometres and "went through all the right channels to raise their questions".

“We have come to the other side of the world to tell these big bosses that what Exxon are doing to our community is wrong. I wanted to tell them that cutting our pay and starving us into submission is wrong. But they won’t even let me say that,” he said.