I think you might be addressing the part where I said we could still have a basically two-party system. I meant that the two main parties could still maintain their influence, but that minority parties could finally stand a chance of exerting some influence during elections as well as on the floor of either house when it becomes necessary to form a governing coalition. Isn't that pretty much of a necessity in Britain? As it is third parties never stand a chance of ever getting elected to a meaningful degree.
Not usually, no. The current Conservative government has an 80 seat majority, holding 365 of the 650 commons seats. Labour hold 202 seats, with the largest third party being the Scottish Nationalists with 48. The rest of the parties have a total of 35 seats between them; The Liberal Democrats having the largest number of these at 11.
The remaining 24 are mostly Northern Ireland seats, which have their own set of parties, split on mainly sectarian lines (there are seven Sinn Fein and eight Democratic Unionist seats, with three seats going to two non-sectarian parties. The DUP are Democratic in much the same way that the DPRK is, or the DDR was, and are the rabid protestant and unionist counterpoint to Sinn Fein's rabid catholic and republican position; Sinn Fein was closely associated with the IRA during the 'Troubles', and the DUP was similarly associated with various unionist terrorist groups).
There's also four Welsh nationalist (Plaid Cymru) seats.
It's not unheard of for one of the two main parties to require a coalition partner in order to secure a majority, but it's fairly unusual, and rarely produces a stable government. Typically either the PM in such a 'hung parliament' will call an election if he believes that this will result in a majority for his party; Or the leader of the opposition will push a vote of no confidence through the house, forcing an election, if he believes the government will lose.