LONDON - Britain needs changes to the European Union's founding treaties to protect the reforms it is seeking on issues like welfare from being challenged in European courts, Foreign Secretary Philip Hammond said on Sunday.
Prime Minister David Cameron is seeking to reshape Britain's ties with the EU before putting the country's continuing membership to a public vote before the end of 2017.
One of the biggest hurdles to Cameron's renegotiation is the subject of treaty change, something which Britain says it needs, but which other European leaders are reluctant to consider.
"We think some of the changes in particular that we're demanding around availability of welfare benefits for new migrants from the EU can only be sustained against judicial attack in the European Courts by treaty change," Hammond told the BBC on Sunday.
"It's not treaty change for its own sake, it's treaty change in order to protect the real material changes that we need to get."
German Chancellor Angela Merkel, who will play a leading role in negotiations with Britain, appeared not to rule out treaty change in an interview with the BBC last week.
"If that is really necessary, then we have to think about it," she said. "It's not about losing sleep over this, but about doing our work and creating the necessary preconditions for Britain to remain in the EU."
Some EU officials have spoken of the possibility of special"opt-outs" for Britain on certain issues, avoiding the necessity of treaty change that can involve parliamentary votes or referendums in member nations.