Britain's Prime Minister Theresa May is pictured outside the Houses of Parliament, in London, Britain, February 14, 2019. REUTERS/Hannah McKay

LONDON (Reuters) - Prime Minister Theresa May was defeated in a symbolic vote in parliament on her Brexit strategy on Thursday, undermining her negotiating strength in talks with the European Union to secure changes to the agreement.

MPs voted by 303 to 258 to reject a motion asking them to reaffirm support for May’s plan to seek changes to her Brexit deal. Many pro-Brexit members of her Conservative Party planned to abstain on the vote as they feared she was softening her position on a no-deal departure.