By City A.M. Reporter Aslef’s lead negotiator has said the union is putting “members first” in a “toxic situation” after announcing a fresh series of strikes. Train drivers working for LNER – which runs the passenger service on the East Coast main line between London and Edinburgh – will walk out on weekends from the end of August in a dispute about working agreements. The dispute is separate from the long-running row over pay, which looks likely to be resolved after a new offer this week from the Government. Lead negotiator Nigel Roebuck told Times Radio: “We work within agreements, we jointl…