The phrase 'severely undermining' is correct and can be used in written English.
You can use it to describe a situation in which someone or something is having a very negative impact on another something, for example: "The government's new policies are severely undermining businesses across the country."
The caves now suffer from high levels of carbon dioxide and humidity, which are severely undermining conservation efforts.
"Assisted suicide and euthanasia will radically change the social air we all breathe by severely undermining respect for life," it argued.
First he blamed Congress for severely undermining the policy in Lebanon, thus focussing attention on his Lebanon policy, which has been nearly forgotten.
But nor were there interviews with local councillors, whose budgets have been squeezed since 2010, severely undermining their ability to plan for disasters.
Liam Burns, president of the National Union of Students, said the blocking of Ebdon's appointment "risked severely undermining attempts to ensure fair access to universities".
Nevertheless, Cypriot officials have expressed concern that a potential Greek exit from the euro could dent the country's prospects, severely undermining investor confidence and foreign deposits, which so far have remained stable.
However, sustained low prices could severely undermine fiscal resources and external balances in several already fragile oil-exporting economies in the Middle East, Europe and Central Asia, and Latin America.
"Not disclosing conflicts, to me, severely undermines your credibility".
However, the poor, lifeless base severely undermines its chances.
It severely undermined relations between the US and Pakistan.
"This fiasco severely undermines the mayor's credibility," said Robin Brown, the president of the United Parents Association.
