Scottish Conservative leader Ruth Davidson told her party on Friday that "too many of our fellow Scots simply don't trust our motives,".
Ms Davidson was elected Scottish Tory leader in November 2011 but has so far failed to improve the party's low standing in the polls.
She told party members: "I'm not going to stand here and claim that the decline in our vote over the last two decades is somehow all down to poor marketing.
"We need to admit something to ourselves, however hard it may be - that the Scottish public did indeed get our message, that they heard us very clearly.
"And in far too many cases they simply didn't like what they were hearing, or what we were offering."
However the speech contained no changes in the policy positions that have made the Tories so unpopular in Scotland.
Foreign Minister Alistair Burt's admission that the Cameron government has "supported" a survey of attitudes to US drone strikes in Pakistan's tribal areas amounts to a tacit admission of British involvement.