LONDON (Reuters) - The newly installed leader of the semi-autonomous government of Wales, Vaughan Gething, was left weakened on Friday when the nationalist Plaid Cymru party ended its cooperation agreement with his Welsh Labour party.

Rhun ap Iorwerth, Plaid Cymru's leader, said he pulled the party out of the deal due to his concerns about a 200,000-pound ($254,140) donation to Gething's party leadership campaign from a firm convicted of environmental offences and other issues.

Plaid Cymru's agreement to support Labour in the Welsh parliament had been due to expire at the end of this year.

Gething became the first minister of the Welsh government in March and he will now have to muster support from other parties to push through legislation.

The collapse of the Labour-Plaid Cymru partnership follows the breakdown of a similar deal between the Scottish National Party and the Scottish Greens that led to the resignation of Humza Yousaf as Scotland's first minister in April.

The Welsh government has responsibility for areas including health and education.

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(Reporting by William Schomberg; Editing by Sandra Maler)