Concerned about the continuing viability of the Grand Union Canal as a route for additional traffic for their own canal, in late 1886, the Grand Junction company inspected the Grand Union Canal and the Leicestershire and Northamptonshire Union Canal, and wrote to both, about the possible measures to increase traffic. Both indicated they were prepared to sell out to the Grand Junction, who offered £5,000 for the two. The two “Union” canals countered with an offer of £25,000, since they had a large asset in their water supplies, particularly at Welford, which also fed down to the Grand Junction Norton summit, but no agreement was made.

In 1893, Joshua Fellows, of the canal carrying company, Fellows, Morton & Clayton, suggested that widening the locks at Foxton and Watford and dredging the canal would allow them to run large steam boats and to compete better with the railways. After discussion, Fellows was offered both of the canals for £20,000 which he bought as agent for the Grand Junction company for a final price of £10,500 for the Grand Union and £6,500 for the Leicestershire and Northamptonshire Union. The transfer of ownership took place on 29th September 1894 following an Act of Parliament to authorise the takeover. After takeover, these canals became known as the Leicester Line of the Grand Junction Canal.

The Grand Junction negotiated with the Leicester, Loughborough, and Erewash Canals to agree tolls for through traffic and, realising that the narrow locks at Foxton and Watford were the only obstacle to wide-beam barge traffic between the coalfields and London, initiated a project for an inclined plane boat lift at Foxton. Two counterbalanced caissons, each able to hold two narrowboats or a wide beam barge, raised or lowered boats the 75 feet to and from the summit level in twelve minutes. The inclined plane began operating in July 1900

Due to the complexity and cost of the inclined plane project at Foxton, the Grand Junction Company decided against a second inclined plane at Watford and decided rather to widen the locks. However, coal traffic continued to decline and between November 1901 and February 1902 Watford locks were rebuilt – but to the narrow seven feet gauge. The Foxton lock flight was re-opened in 1906, initially for night-time passage, and the inclined plane stopped operating in November 1910, being dismantled and sold for scrap in the 1920's.