(CNN) Mitt Romney has instructed his closest advisers to explore the possibility of stopping Donald Trump at the Republican National Convention, a source close to Romney's inner circle says.
The 2012 GOP nominee's advisers are examining what a fight at the convention might look like and what rules might need revising.
"It sounds like the plan is to lock the convention," said the source.
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Romney is focused on suppressing Trump's delegate count to prevent him from accumulating the 1,237 delegates he needs to secure the nomination.