New Zealand First leader Winston Peters says any scale-back in funding to the foreign affairs portfolio will be a serious mistake.
Finance Minister Michael Cullen warned that funding may have to be reduced, following the release of the pre-election economic and fiscal update showing Government accounts in deficit.
During Winston Peters' tenure as Foreign Affairs Minister, he secured a $621 million increase to the portfolio in the 2008 Budget.
He says the country is already suffering the consequences of a lack of investment in the foreign affairs area.
"We've never had the staff offshore for the last 14 years, never had the investment or the capability to help our businessmen and businesswomen offshore, and that export outcome is proof of that."
Mr Peters says it is short-sighted and silly for the government to believe it can get by in a more competitive world, without making that investment.