A second activist investor has questioned the leadership of Glaxosmithkline plc’s CEO Emma Walmsley, after Bluebell Capital Partners Ltd. took a reported £10 million (US$13.7 million) stake in the embattled U.K. pharma.

Glaxosmithkline plc should stick to its plan to split into two companies, one focused on pharma and the other on consumer health, but must ask itself whether CEO Emma Walmsley is the right person to lead the changes, according to activist investor Elliott Management.