Anglo-Irish independent Tullow Oil is set to book large impairments due to lower near-term oil price forecasts and has flagged up a delay to the long-awaited final investment decision on its project in Kenya amid the Covid-19 impacts on its work programme.

Tullow said in a trading statement on Wednesday that it expects to announce between $1.4 billion and $1.7 billion in impairments before tax in its half-year results, due on 9 September.

The move comes as a result of lower near-term oil price forecasts, and a revision in the group’s long-term oil price assumption from $65 per barrel to $60 per barrel.